Exception code: 0xc0000005

That is a crash caused by an Access Violation. Unfortunately, that's a very broad error which we can't really diagnose without a debug build.

The only realistic way forward is to delete the entire Qt folder and its settings (see mrjj's post above) and try again.

Faulting application name: MaintenanceTool.exe, version: 4.0.1.0, time stamp: 0x60057b14
Faulting module name: MaintenanceTool.exe, version: 4.0.1.0, time stamp: 0x60057b14
Exception code: 0xc0000005
Fault offset: 0x00053290
Faulting process id: 0x6730
Faulting application start time: 0x01d766b060bd5f9e
Faulting application path: C:\Qt\MaintenanceTool.exe
Faulting module path: C:\Qt\MaintenanceTool.exe
Report Id: cdcfc291-2f1e-4b6e-a821-9d381f54a2b9
Faulting package full name: 
Faulting package-relative application ID:

There are no further details unfortunately.

I want to see if there is anything more that I can do to help diagnose the issue

You could check the Windows event log (in mmc tool)

but the 5.12.2 subdirectory is actually above 50 GB

Only if you select ALL Qt builds!
Select only Qt builds you really need...

@JKSH said in Uninstaller doesn't work:

If you log in as another (admin) user, do you get the same outcome?

I'm afraid I cannot try this, as I only have access to my own user on this pc (it is a company machine).

What is the size of your Qt folder's contents?

• MaintenanceTool.exe should be about 23 MB
• Each version of Qt should be about 500 -- 600 MB

MaintenanceTool.exe has the size you specified, but the 5.12.2 subdirectory is actually above 50 GB (if I'm looking at the correct directory) - see the linked image:

Also, when you open Windows 10 Settings > Apps, do you see Qt listed as one of the things that can be uninstalled?

Yes, it is listed (I included it in the above screenshot), but pressing Uninstall has no visible effect.

@SzT22 said in Uninstaller doesn't work:

I have the same problem: if I run MaintenanceTool.exe in any form it just exits immediately. Running it as administrator, or from a command line (that was opened as administrator) has the same effect, the program exits right away without opening a window or writing any message to the console.

If you log in as another (admin) user, do you get the same outcome?

Unfortunately I don't remember if the installer finished successfully - looking in InstallationLog.txt I only found one warning, at line 17 (see below), with around 17000 lines after that.

[21270] Warning: Network error while downloading 'https://download.qt.io/online/qtsdkrepository/windows_x86/desktop/tools_maintenance/2020-12-03-0501_meta.7z': Error transferring https://download.qt.io/online/qtsdkrepository/windows_x86/desktop/tools_maintenance/2020-12-03-0501_meta.7z - server replied: Not Found.

That seems to indicate that something didn't download.

What is the size of your Qt folder's contents?

• MaintenanceTool.exe should be about 23 MB
• Each version of Qt should be about 500 -- 600 MB

Also, when you open Windows 10 Settings > Apps, do you see Qt listed as one of the things that can be uninstalled?

I have the same problem: if I run MaintenanceTool.exe in any form it just exits immediately. Running it as administrator, or from a command line (that was opened as administrator) has the same effect, the program exits right away without opening a window or writing any message to the console.

I also use Windows 10, and tried to install Qt version 5.15.2 back in January.

Unfortunately I don't remember if the installer finished successfully - looking in InstallationLog.txt I only found one warning, at line 17 (see below), with around 17000 lines after that.

[21270] Warning: Network error while downloading 'https://download.qt.io/online/qtsdkrepository/windows_x86/desktop/tools_maintenance/2020-12-03-0501_meta.7z': Error transferring https://download.qt.io/online/qtsdkrepository/windows_x86/desktop/tools_maintenance/2020-12-03-0501_meta.7z - server replied: Not Found.

@An0n said in Uninstaller doesn't work:

I've tried some fixes but they also didn't work

What fixes did you try?

If I try to uninstall it via the uninstaller itself, via the win10 uninstaller, or een by running MaintenenceTool.exe directly, nothing happens.

What happens if you run MaintenanceTool.exe as Administrator? (Right-click > "Run as Administrator")

What happens if you run it from the command line? Do you see any error messages?

Sorry but i dont know who to fix this as it sounds the install is incomplete and might miss uninstall files etc.