MacOS: Screenshot doesn't work

HeinrichfromGelnhausen wrote:

Screenshot works fine on Admin and wife's account.

That tells us the you have some 3rd party software installed that is causing the problem.

Download and run Etrecheck. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

IMPORTANT:

Before running Etrecheck assign Full Disk Access to Etrecheck in the Etrecheck's Privacy preference pane so that it can get additional information from the Console and log files for the report:

Also click and read the About info to further permit full disk access.

Copy the report

and use the Additional Text button to include the report in your reply.

Then we can examine the report and see if we can determine what might be causing the problem.

Try starting up in Safe Mode followed by a normal restart,

see > https://support.apple.com/en-us/HT201262

then test the Command + Shift + 4 screenshot.

see > https://support.apple.com/en-us/HT201361

If that doesn't help, then compare what App's and Startup Items are different in the accounts.

This is what a Safe Mode boot does:

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

There's often a damaged cache file that causes problems and a Safe Mode boot clears them out and starts over fresh. It's a good first fix attempt when things are acting wonky.

Delete CleanMyMac. It is 100% junk and akin to malware.

The best antivirus, cleaning app, and overall maintenance app for Mac OS is Mac OS itself. All you need to do with Mac OS to keep it secure and running well is to keep it up-to-date and do periodic (about 1x per week) restarts. Other than that, leave it alone. Adding third party antivirus, cleaning, security and other types of maintenance apps to Mac OS adds no additional level of security. The only thing these apps do is have the opposite affect users want. They make Mac OS slow, unstable, generate odd behavior (much like you are experiencing) and make Mac OS appear buggy.

Please locate the developers uninstall instructions for CleanMyMac and follow to the letter. Then restart in Safe Mode per the directions in Use safe mode to isolate issues with your Mac and then restart normally.

The 2nd major issue is this computer does not appear to be backed up. If this is correct this is short sighted and a guarantee of lost data. At the very least you should be using Time Machine!!! If you are unfamiliar with TM please refer to Back up your Mac with Time Machine - Apple Support. The only thing you need is a high quality external HD such as a OWC Mercury Elite Pro. If you are located outside the USA and want one of these drives please let us know and we can send you a link to a distributor or reseller in your general area.

Command + Shift + 4 is for taking a Portion screenshot.

Command + Shift + 5 is for setting the timer and were the screenshot is saved.

Please review > https://support.apple.com/en-us/HT201361

and > https://support.apple.com/guide/mac-help/take-a-screenshot-or-screen-recording-mh26782/mac

+2 CleanMyMac is junkware and needs to go.

Use Safe Mode as instructed by everyone that has replied thus far.

You also have a lot of third party App's set to open at Login, which are hogging valuable resources. Go to Apple > System Preferences > Users & Accounts > select Login Items and remove any of those that are not necessary.

Please do as instructed it will likely solve the issue. If for some reason it does not please do the following:

Please navigate to www.Etrecheck.com and download the free version of EtreCheck. Once you have you downloaded the app and installed it, please run the report and save it. This report will help us get a good idea what has been installed on your system and help us be able to diagnose what may be wrong.

When you have your report, you can attach it when you reply to this message and we can then review it and help you determine what is needed to get your system running well again.

For instructions on how to download your EtreCheck report and attach it to your reply to this message please click https://discussions.apple.com/docs/DOC-250000211

The possible cause is because CMM modifies and damages Mac OS and has a long history of doing so. As long as you continue using it your issues will likely continue. Please remember you came to these forums seeking advice and we have offered advice that works for most users. If you do not want to accept, well then the very best of luck.

As for your backup plan, please remember that iCloud is NOT a backup plan it is a storage plan. Apple's backup solution is using Time Machine. Doing hand backups is also flawed as you have to remember it, using Time Machine and/or a bootable clone backup is automatic and needs nothing more than a periodic check to ensure it is still working. Most experienced users on these forums use redundant backups because because backups fail too.