My iMac is behaving very slow after the last update OS Catalina

As John noted, you still have lots of pieces of AVG installed. That can cause the Mac to run worse because it's now looking for broken, or missing pieces of itself.

This won't get rid of every single thing AVG may have spread around the drive, but it will remove the parts that are still trying to be active. Put the following in the trash.

Root /Library/LaunchAgents/ folder:

com.avg.hub.plist

Root /Library/LaunchDaemons/ folder:

com.avg.hub.schedule.plist

com.avg.hub.xpc.plist

Root /Library/Application Support/ folder:

Delete the entire subfolder, AVGHUB .

Restart the Mac and then empty the trash. This should clear the rest of anything of AVG that matters.

~~~~~~~~~~~~~~~~~~~~~

You also have lots of useless junk installed that do nothing but waste system resources.

Unless you have a very specific need for them (such as a poorly maintained web site that still requires them to function), remove Flash and Java. I haven't had either installed since Mojave and don't miss them at all.

Flash uninstaller

Java uninstaller

As mentioned by Luis, Flip4Mac, Silverlight, Perian and MacFUSE are all outdated software. I don't think any of them even function in Catalina.

Do yourself and your Mac a favor and remove anything written by Google. In your case, I would presume Chrome. I really, truly don't understand what people think is so great about this browser. For starters, it's a known, massive resource hog. Worse, the daemons it installs track every single thing you do on your computer and upload it as anonymized data to Google's servers. It does this the entire time your computer is on, whether Chrome itself is running or not. Google's true business is collecting and selling marketing data. You are their willing and unpaid participant when using any of their apps.

Put these items in the trash:

The Chrome app itself.

Root /Library/LaunchAgents/ folder:

com.google.keystone.agent.plist

com.google.keystone.xpcservice.plist

Root /Library/LaunchDaemons/ folder:

com.google.keystone.daemon.plist

Restart the Mac and empty the trash.

boehda wrote:

Leroy,

this is the report of de Major issues,

I could not find the button to Allow full Disk Acces

<Report Major issues.log>

<Runtime: 20:06>

< /Applications/AVGAntivirus.app>

Use the official uninstaller to remove the third party Anti-Virus this cause nothing but added issues with the macOS.

Look in-app or refer to the developers website if in doubt.

This has impacted your drive—A properly functioning drive should complete the ertrecheck in ~ 3 minutes.

+1

Definitely uninstall AVG according to the developer's instructions. Look at Page 14 and 18 of the AVG User Manual. You can download it at the link I provided.

Just be aware that there's no need to ever run any "cleaning", "optimizing", "speed-up" or anti-virus apps. Read this user tip on protecting your Mac: Effective defenses against malware and other threats - Apple Community   

boehda wrote:

My IMac is behaving very slow after the last update OS Catalina.

Also the display shows flashes, colored red, mouse falls out different times, mail program behaving strange, is this a virus or a system error.

To get a good look at your System config. for conflicts or issues, you can download/run this trusted utility https://etrecheck.com

If you need help interpreting the report you can post it here in its entirety in the "Additional Text" box in the editing toolbar below, in your reply.



You can set its preference to "Allow full Disk Access", with this you get a digest of issues from the last 7 days that are saved in your system. _No_ personal information is revealed.

AVG is still there in bits and pieces.

Plus, you have a lot of old stuff in there (Perian, Flip4mac,...).

You could perhaps try doing a clean install of Catalina on a separate drive and see if it shows the same symptoms.

Luis Sequeira1 wrote:

AVG is still there in bits and pieces.

It may not comfort you to know this now, but I found "AVG" so difficult to eradicate that I gave up and erased the Mac. Their uninstallation instructions did not work and their online support was worthless. They suggested that I contact them over the phone to arrange a screen-sharing session. I declined.

Rule 1 of Macs is don't install junk. It's the first step in a well-worn path to misery.

Parallels will slow down your Mac a lot. You're running a virtual computer in RAM, plus the guest OS. All of that is sharing the same RAM the host OS is trying to use.

The 16 GB of RAM you have installed is a decent amount, but not really enough when you're also running a VM. You then have two OS' running in a barely adequate 8 GB each.

Removing Oracle's Java is very simple. Trash these three items. The tilde ~ means your user account. The first two are the main Library folder.

/Library/Internet Plug-Ins/JavaAppletPlugin.plugin 

/Library/PreferencePanes/JavaControlPanel.prefPane 

~/Library/Application Support/Oracle/Java

You may also want to read these threads

https://discussions.apple.com/thread/251334078

and

https://discussions.apple.com/thread/251259424

I have run EtreCheck and it also says my disk is failing - although I suspect the problem is to do with the Catalina 10.15.4 and Supplemental Update (judging from the number of related problems folks are having)

If you ran EtreCheck after removing Java, then you didn't remove it as the items are still listed as present.

The author of EtreCheck has noted that a hard drive may get listed as failing when there's nothing wrong with it. Part of what it does is time how long it takes to do the various checks. If, per the model Mac and rotational speed of the drive, it takes longer than xxx minutes/seconds to complete, the assumption is made the drive is failing.

So, the drive might be okay. But it also really could be going south.

There you have it, very clearly in the report: your drive is failing.

Major Issues:
  Anything that appears on this list needs immediate attention. 
  Failing hard drive - This machine has a hard drive that appears to be failing.
  Runaway process - A process is using a large percentage of your CPU.
  Software/hardware problems - Software is causing performance problems.

It may be a good thing in the end.

Your mac will work so much better with an SSD.

You can install onto a 1TB external SSD, connected via USB3, and your mac will perform so much better.