After the latest updat to Mavericks 10.9.3, my imac continues to loop back to the login screen...Suggestions??? THANK YOU VERY MUCH!

1. This procedure is a diagnostic test. It changes nothing, for better or worse, and therefore will not, in itself, solve the problem. But with the aid of the test results, the solution may take a few minutes, instead of hours or days.

2. If you don't already have a current backup, back up all data before doing anything else. The backup is necessary on general principle, not because of anything in the test procedure. Backup is always a must, and when you're having any kind of trouble with the computer, you may be at higher than usual risk of losing data, whether you follow these instructions or not.

There are ways to back up a computer that isn't fully functional. Ask if you need guidance.

3. Below are instructions to run a UNIX shell script, a type of program. All it does is to collect information about the state of the computer. That information goes nowhere unless you choose to share it. However, you should be cautious about running any kind of program (not just a shell script) at the request of a stranger. If you have doubts, search this site for other discussions in which this procedure has been followed without any report of ill effects. If you can't satisfy yourself that the instructions are safe, don't follow them. Ask for other options.

Here's a summary of what you need to do, if you choose to proceed:

☞ Copy a line of text in this window to the Clipboard.

☞ Paste into the window of another application.

☞ Wait for the test to run. It usually takes a few minutes.

☞ Paste the results, which will have been copied automatically, back into a reply on this page.

The sequence is: copy, paste, wait, paste again. You don't need to copy a second time. Details follow.

4. You may have started the computer in "safe" mode. Preferably, these steps should be taken in “normal” mode, under the conditions in which the problem is reproduced. If the system is now in safe mode and works well enough in normal mode to run the test, restart as usual. If you can only test in safe mode, do that.

5. If you have more than one user, and the one affected by the problem is not an administrator, then please run the test twice: once while logged in as the affected user, and once as an administrator. The results may be different. The user that is created automatically on a new computer when you start it for the first time is an administrator. If you can't log in as an administrator, test as the affected user. Most personal Macs have only one user, and in that case this section doesn’t apply. Don't log in as root.

6. The script is a single long line, all of which must be selected. You can accomplish this easily by triple-clicking anywhere in the line. The whole line will highlight, though you may not see all of it in the browser window, and you can then copy it. If you try to select the line by dragging across the part you can see, you won't get all of it.

Triple-click anywhere in the line of text below on this page to select it:

PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/libexec;clear;cd;p=(Software Hardware Memory Diagnostics Power FireWire Thunderbolt USB Fonts 51 4 1000 25 5120 KiB/s 1024 85 \\b%% 20480 1 MB/s 25000 ports 'com.autodesk.AutoCad com.evenflow.dropbox com.google.GoogleDrive' DYLD_INSERT_LIBRARIES\ DYLD_LIBRARY_PATH -86 ` route -n get default|awk '/e:/{print $2}' ` 25 N\\/A down up 102400 25600 recvfrom sendto CFBundleIdentifier 25 25 25 1000 MB );N5=${#p[@]};p[N5]=` networksetup -listnetworkserviceorder|awk ' NR>1 { sub(/^\([0-9]+\) /,"");n=$0;getline;} $NF=="'${p[45]}')" { sub(/.$/,"",$NF);print n;exit;} ' `;f=('\n%s: %s\n' '\n%s\n\n%s\n' '\nRAM details\n%s\n' %s\ %s '%s\n\t(%s)\n' );S0() { echo ' { q=$NF+0;$NF="";u=$(NF-1);$(NF-1)="";gsub(/^ +| +$/,"");if(q>='${p[$1]}')printf("%s (UID %s) is using %s '${p[$2]}'",$0,u,q);} ';};s=(' /^ *$|CSConfigDot/d;s/^ */ /;s/[-0-9A-Fa-f]{22,}/UUID/g;s/(ochat)\.[^.]+(\..+)/\1\2/;/Shared/!s/\/Users\/[^/]+/~/g ' ' s/^ +//;5p;6p;8p;12p;' ' {sub(/^ +/,"")};NR==6;NR==13&&$2<'${p[10]} ' 1s/://;3,6d;/[my].+:/d;s/^ {4}//;H;${ g;s/\n$//;/s: [^EO]|x([^08]|02[^F]|8[^0])/p;} ' ' 5h;6{ H;g;/P/!p;} ' ' ($1~/^Cy/&&$3>'${p[11]}')||($1~/^Cond/&&$2!~/^N/) ' ' /:$/{ s/ *:$//;x;s/\n//;/Apple|Capacity:|Genesy|Intel|SMSC/d;s/\n.*//;/\)$/p;};/^ *(V.+ [0N]|Man).+ /{ s/ 0x.... //;s/[()]//g;s/(.+: )(.+)/ (\2)/;H;} ' ' s/^.*C/C/;H;${ g;/No th|pms/!p;} ' '/= [^GO]/p' '{$1=""};1' ' /Of/!{ s/^.+is |\.//g;p;} ' ' $0&&!/:/;END { if(NR<100)print "com.apple.";} ' ' $3~/[0-9]:[0-9]{2}$/ { gsub(/:[0-9:a-f]{14}/,"");} { print|"tail -n'${p[12]}'";} ' ' NR==2&&$4<='${p[13]}' { print $4;} ' ' END { $2/=256;if($2>='${p[15]}')print int($2) } ' ' NR!=13{next};{sub(/[+-]$/,"",$NF)};'"`S0 21 22`" 'NR==2'"`S0 37 17`" ' NR!=5||$8!~/[RW]/{next};{ $(NF-1)=$1;$NF=int($NF/10000000);for(i=1;i<=3;i++){$i="";$(NF-1-i)="";};};'"`S0 19 20`" 's:^:/:p' '/\.kext\/(Contents\/)?Info\.plist$/p' ' s/^.{52}//;s/ .+//p ' ' /Launch[AD].+\.plist$/;END{if(NR<100)print "/System/";} ' '/\.xpc\/(Contents\/)?Info\.plist$/p' ' NR>1&&!/0x|\.[0-9]+$|com\.apple\.launchctl\.(Aqua|Background|System)$/ { print $3;} ' ' /\.(framew|lproj)|\):/d;/plist:|:.+(Mach|scrip)/s/:[^:]+//p ' '/root/p' ' !/\/Contents\/.+\/Contents|Applic|Autom|Frameworks/&&/Lib.+\/Info.plist$/;END{if(NR<100)print "/System/"};' '/^\/usr\/lib\/.+dylib$/p' '/\/etc\/(auto_m|hosts[^.]|peri)/s/^\.\/[^/]+//p' ' /\/(Contents\/.+\/Contents|Frameworks)\//d;p;' 's/\/(Contents\/)?Info.plist$//;p' ' { gsub("^| ","||kMDItem'${p[35]}'=");sub("^.."," ") };1 ' p '{print $3"\t"$1}' 's/\'$'\t''.+//p' 's/1/On/p' '/Prox.+: [^0]/p' '$2>'${p[9]}'{$2=$2-1;print}' ' BEGIN { i="'${p[26]}'";M1='${p[16]}';M2='${p[18]}';M3='${p[31]}';M4='${p[32]}';} !/^A/ { next;} /%/ { getline;if($5M2 { b=$3" ops/s, "$4" blocks/s";} $2==i { if(c) { d=$3+$4+$5+$6;next;};if($4>M3||$6>M4) c=int($4/1024)" in, "int($6/1024)" out";} END { if(a) print "CPU: "a;if(b) print "I/O: "b;if(c) print "Net: "c" (KiB/s)";if(d) print "Net errors: "d" packets/s";} ' ' /r\[0\] /&&$NF!~/^1(0|72\.(1[6-9]|2[0-9]|3[0-1])|92\.168)\./ { print $NF;exit;} ' ' !/^T/ { printf "(static)";exit;} ' '/apsd|OpenD/!s/:.+//p' ' (/k:/&&$3!~/(255\.){3}0/ )||(/v6:/&&$2!~/A/ ) ' ' /lR/ { if($2<='${p[25]}')print $2;} ' ' BEGIN { FS=":";} $3~/(sh|ng|ic)$/ { n=split($3,a,".");sub(/_2[01].+/,"",$3);b=b"\n"$2" "$3" "a[n]" "$1;c=c$1;} END { d="sort|tail -n'${p[38]}'";print b|d;close(d);if(c)print("\n\t* Code injection");} ' ' NR!=4{next} {$NF/=10240} '"`S0 27 14`" ' END { if($3~/[0-9]/)print$3;} ' ' BEGIN { L='${p[36]}';} !/^[[:space:]]*(#.*)?$/ { l++;if(l<=L) f=f"\n "$0;} END { F=FILENAME;if(!F) exit;if(!f) f="\n [N/A]";"file -b "F|getline T;if(T!~/^(A.+ E.+ text$|POSIX sh.+ text ex)/) F=F" ("T")";printf("\nContents of %s\n%s\n",F,f);if(l>L) printf("\n ...and %s more line(s)\n",l-L);} ' ' BEGIN{FS="= "} /Path/{print $2} ' ' /^ +B/{ s/.+= |(-[0-9]+)?\.s.+//g;p;} ' ' END{print NR} ' ' /id: N|te: Y/{i++} END{print i} ' ' /:/{$0="'"${p[28]}"'"};1;' '/ en/!s/\.//p' ' NR!=13{next};{sub(/[+-M]$/,"",$NF)};'"`S0 39 40`" );c1=(system_profiler pmset\ -g nvram fdesetup find syslog df vm_stat sar ps sudo\ crontab sudo\ iotop top pkgutil PlistBuddy whoami cksum kextstat launchctl sudo\ launchctl crontab 'sudo defaults read' stat lsbom mdfind ' for i in ${p[24]};do ${c1[18]} ${c2[27]} $i;done;' defaults\ read scutil sudo\ dtrace sudo\ profiles sed\ -En awk /S*/*/P*/*/*/C*/*/airport networksetup mdutil );c2=(com.apple.loginwindow\ LoginHook '-c Print /L*/P*/loginw*' '-c Print L*/P*/*loginit*' '-c Print L*/Saf*/*/E*.plist' '~ $TMPDIR.. \( -flags +sappnd,schg,uappnd,uchg -o ! -user $UID -o ! -perm -600 \)' '.??* -path .Trash -prune -o -type d -name *.app -print -prune' '-c Print\ :'${p[35]}' 2>&1' '-c Print\ :Label 2>&1' '{/,}L*/{Con,Pref}* -type f ! -size 0 -name *.plist -exec plutil -s {} \;' "-f'%N: %l' Desktop L*/Keyc*" therm sysload boot-args status "-F '\$Time \$Message' -k Sender kernel -k Message Req 'Beac|caug|dead[^bl]|FAIL|GPU |hfs: Ru|inval|jnl:|last value [1-9]|n Cause: -|NVDA\(|pagin|proc: t|Roamed|rror|ssert|Thrott|tim(ed? ?|ing )o|WARN' -k Message Rne 'Goog|ksadm|SMC:' -o -k Sender fseventsd -k Message Req 'SL'" '-du -n DEV -n EDEV 1 10' 'acrx -o comm,ruid,%cpu' '-t1 10 1' '-f -pfc /var/db/*/*.{BS,Bas,Es,OSXU,Rem}*.bom' '{/,}L*/Lo*/Diag* -type f \( -exec grep -lq "^Thread c" {} \; -exec printf \* \; -o -true \) -execdir stat -f:%Sc:%N -t%F {} \;' '-L {/{S*/,},}L*/Lau* -type f' '-L /{S*/,}L*/StartupItems -type f -exec file {} +' '-L /S*/L*/{C*/Sec*A,E}* {/,}L*/{A*d,Compon,Ex,In,iTu,Keyb,Mail/B,P*P,Qu*T,Scripti,Sec,Servi,Spo}* -type f -name Info.plist' '/usr/lib -type f -name *.dylib' `awk "${s[31]}"<<<${p[23]}` "/e*/{auto_master,{cron,fs}tab,hosts,{launchd,sysctl}.conf} /usr/local/etc/periodic/*/* .launchd.conf" list getenv /Library/Preferences/com.apple.alf\ globalstate --proxy '-n get default' -I --dns -getdnsservers -getinfo\ "${p[N5]}" -P -m\ / '' -n1 '-R -l1 -n1 -o prt -stats command,uid,prt' '--regexp --only-files --files com.apple.pkg.*|sort|uniq' -kl -l -s\ / '-R -l1 -n1 -o mem -stats command,uid,mem' );N1=${#c2[@]};for j in {0..8};do c2[N1+j]=SP${p[j]}DataType;done;N2=${#c2[@]};for j in 0 1;do c2[N2+j]="-n ' syscall::'${p[33+j]}':return { @out[execname,uid]=sum(arg0) } tick-10sec { trunc(@out,1);exit(0);} '";done;l=(Restricted\ files Hidden\ apps 'Elapsed time (s)' POST Battery Safari\ extensions Bad\ plists 'High file counts' User Heat System\ load boot\ args FileVault Diagnostic\ reports Log 'Free space (MiB)' 'Swap (MiB)' Activity 'CPU per process' Login\ hook 'I/O per process' Mach\ ports kexts Daemons Agents launchd Startup\ items Admin\ access Root\ access Bundles dylibs Apps Font\ issues Inserted\ dylibs Firewall Proxies DNS TCP/IP RSSI Profiles Root\ crontab User\ crontab 'Global login items' 'User login items' Spotlight Memory );N3=${#l[@]};for i in 0 1 2;do l[N3+i]=${p[5+i]};done;N4=${#l[@]};for j in 0 1;do l[N4+j]="Current ${p[29+j]}stream data";done;A0() { id -G|grep -qw 80;v[1]=$?;((v[1]==0))&&sudo true;v[2]=$?;v[3]=`date +%s`;clear;};for i in 0 1;do eval ' A'$((1+i))'() { v=` eval "${c1[$1]} ${c2[$2]}"|'${c1[30+i]}' "${s[$3]}" `;[[ "$v" ]];};A'$((3+i))'() { v=` while read i;do [[ "$i" ]]&&eval "${c1[$1]} ${c2[$2]}" \"$i\"|'${c1[30+i]}' "${s[$3]}";done<<<"${v[$4]}" `;[[ "$v" ]];};A'$((5+i))'() { v=` while read i;do '${c1[30+i]}' "${s[$1]}" "$i";done<<<"${v[$2]}" `;[[ "$v" ]];};';done;A7(){ v=$((`date +%s`-v[3]));};B2(){ v[$1]="$v";};for i in 0 1;do eval ' B'$i'() { v=;((v['$((i+1))']==0))||{ v=No;false;};};B'$((3+i))'() { v[$2]=`'${c1[30+i]}' "${s[$3]}"<<<"${v[$1]}"`;} ';done;B5(){ v[$1]="${v[$1]}"$'\n'"${v[$2]}";};B6() { v=` paste -d: <(printf "${v[$1]}") <(printf "${v[$2]}")|awk -F: ' {printf("'"${f[$3]}"'",$1,$2)} ' `;};B7(){ v=`grep -Fv "${v[$1]}"<<<"$v"`;};C0(){ test "$v"&&echo "$_";};C1() { [[ "$v" ]]&&printf "${f[$1]}" "${l[$2]}" "$v";};C2() { v=`echo $v`;[[ "$v" != 0 ]]&&C1 0 $1;};C3() { v=`sed -E "$s"<<<"$v"`&&C1 1 $1;};for i in 1 2;do for j in 2 3;do eval D$i$j'(){ A'$i' $1 $2 $3; C'$j' $4;};';done;done;A0;{ A2 0 $((N1+1)) 2;C0;A1 0 $N1 1;C0;B0;C2 27;B0&&! B1&&C2 28;D12 15 37 25 8;A1 0 $((N1+2)) 3;C0;D13 0 $((N1+3)) 4 3;D22 0 $((N1+4)) 5 4;for i in 0 1 2;do D13 0 $((N1+5+i)) 6 $((N3+i));done;D13 1 10 7 9;D13 1 11 8 10;D22 2 12 9 11;D12 3 13 10 12;D23 4 19 44 13;D23 5 14 12 14;D22 6 36 13 15;D22 7 37 14 16;D23 8 15 38 17;D22 9 16 16 18;B1&&{ D22 11 17 17 20;for i in 0 1;do D22 28 $((N2+i)) 45 $((N4+i));done;};D22 12 44 54 45;D22 12 39 15 21;A1 13 40 18;B2 4;B3 4 0 19;A3 14 6 32 0;B4 0 5 11;A1 17 41 20;B7 5;C3 22;B4 4 6 21;A3 14 7 32 6;B4 0 7 11;B3 4 0 22;A3 14 6 32 0;B4 0 8 11;B5 7 8;B1&&{ A2 19 26 23;B7 7;C3 23;};A2 18 26 23;B7 7;C3 24;A2 4 20 21;B7 6;B2 9;A4 14 7 52 9;B2 10;B6 9 10 4;C3 25;D13 4 21 24 26;B4 4 12 26;B3 4 13 27;A1 4 22 29;B7 12;B2 14;A4 14 6 52 14;B2 15;B6 14 15 4;B3 0 0 30;C3 29;A1 4 23 27;B7 13;C3 30;D23 24 24 32 31;D13 25 37 32 33;A1 23 18 28;B2 16;A2 16 25 33;B7 16;B3 0 0 34;B2 21;A6 47 21&&C0;B1&&{ D13 21 0 32 19;D13 10 42 32 40;D22 29 35 46 39;};D23 14 1 48 42;D12 34 43 53 44;D22 0 $((N1+8)) 51 32;D13 4 8 41 6;D12 26 28 35 34;D13 27 29 36 35;A2 27 32 39&&{ B2 19;A2 33 33 40;B2 20;B6 19 20 3;};C2 36;D23 33 34 42 37;D22 32 31 43 38;D23 20 42 32 41;D23 14 2 48 43;D13 4 5 32 1;D22 4 4 50 0;D13 14 3 49 5;D23 22 9 37 7;A7;C2 2;} 2>/dev/null|pbcopy;exit 2>&-

exec bash

9. If you're logged in as an administrator, you'll be prompted for your login password. Nothing will be displayed when you type it. You will not see the usual dots in place of typed characters. Make sure caps lock is off. Type carefully and then press return. You may get a one-time warning to be careful. If you make three failed attempts to enter the password, the test will run anyway, but it will produce less information. In most cases, the difference is not important. If you don't know the password, or if you prefer not to enter it, press the key combination control-C or just press return three times at the password prompt. Again, the script will still run.

If you're not logged in as an administrator, you won't be prompted for a password. The test will still run. It just won't do anything that requires administrator privileges.

10. The test may take a few minutes to run, depending on how many files you have and the speed of the computer. A computer that's abnormally slow may take longer to run the test. While it's running, there will be nothing in the Terminal window and no indication of progress. Wait for the line

to appear. If you don't see it within half an hour or so, the test probably won't complete in a reasonable time. In that case, close the Terminal window and report the results. No harm will be done.

11. When the test is complete, quit Terminal. The results will have been copied to the Clipboard automatically. They are not shown in the Terminal window. Please don't copy anything from there. All you have to do is start a reply to this comment and then paste by pressing command-V again.

At the top of the results, there will be a line that begins with "Model Identifier." If you don't see that, but instead see a mass of gibberish, you didn't wait for the "Process completed" message to appear in the Terminal window. Please wait for it and try again.

If any private information, such as your name or email address, appears in the results, anonymize it before posting. Usually that won't be necessary.

12. When you post the results, you might see the message, "You have included content in your post that is not permitted." It means that the forum software has misidentified something in the post as a violation of the rules. If that happens, please post the test results on Pastebin, then post a link here to the page you created.

Note: This is a public forum, and others may give you advice based on the results of the test. They speak only for themselves, and I don't necessarily agree with them.

________________________________

Remove "CleanMyMac" by following the first set of instructions on this page. If you have a different version of the product, the procedure may be different. Do not drag the CleanMyMac application to the Trash.

Back up all data before making any changes.

Some of your user files (not system files) have incorrect permissions or are locked. This procedure will unlock all your user files, reset their ownership, and remove their access-control lists. If you've set special values for those attributes, they will be reverted. In that case, either stop here, or be prepared to recreate the settings if necessary. Do so only after verifying that those settings didn't cause the problem. If none of this is meaningful to you, you don't need to worry about it, but you do need to follow the instructions below.

Step 1

If you have more than one user, and the one in question is not an administrator, then go to Step 2.

Enter the following command in the Terminal window in the same way as before (triple-click, copy, and paste):

{ sudo chflags -R nouchg,nouappnd ~ $TMPDIR..; sudo chown -R $UID:staff ~ $_; sudo chmod -R u+rwX ~ $_; chmod -R -N ~ $_; } 2>&-

This time you'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning to be careful. If you don’t have a login password, you’ll need to set one before you can run the command. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator.

The command may take several minutes to run, depending on how many files you have. Wait for a new line ending in a dollar sign ($) to appear, then quit Terminal.

Step 2 (optional)

Take this step only if you have trouble with Step 1, if you prefer not to take it, or if it doesn't solve the problem.

Start up in Recovery mode. When the OS X Utilities screen appears, select

Utilities ▹ Terminal

from the menu bar. A Terminal window will open. In that window, type this:

res

Press the tab key. The partial command you typed will automatically be completed to this:

resetpassword

Press return. A Reset Password window will open. You’re not going to reset a password.

Select your startup volume ("Macintosh HD," unless you gave it a different name) if not already selected.

Select your username from the menu labeled Select the user account if not already selected.

Under Reset Home Directory Permissions and ACLs, click the Reset button.

Select

 ▹ Restart

from the menu bar.

C.

Spotlight indexing is disabled on the startup volume. I suggest you enable it by removing the volume from the Privacy list in the Spotlight preference pane. There will be a variable delay before the index becomes available, and performance may be slow during that time.

D.

If you're still unable to log in except in safe mode after taking all the above steps, then reinstall the OS.* You don't need to erase the startup volume, and you won't need the backup unless something goes wrong. If the system was upgraded from an older version of OS X, you may need the Apple ID and password you used.

If you use FileVault 2, then before running the Installer you must launch Disk Utility and select the icon of the FileVault startup volume ("Macintosh HD," unless you gave it a different name.) It will be nested below another icon with the same name. Click the Unlock button in the toolbar and enter your login password when prompted. Then quit Disk Utility to be returned to the main Recovery screen.

There are ways to back up a computer that isn't fully functional. Ask if you need guidance.

If you installed the Java runtime distributed by Apple and still need it, you'll have to reinstall it. The same goes for Xcode. All other data will be preserved.

*The linked support article refers to OS X 10.9 ("Mavericks"), but the procedure is the same for OS X 10.7 ("Lion") and later.