Can't install latest Calibre update

[Elaine T]

As the person in the household whose been using calibre the longest I got asked how to fix this. I have no idea.

Daughter, running Windows 11 - as I do - decided to download and install the latest update to Calibre 8.10. She can't. Screenshot of error attached. I suggested trying to run the install as administrator and she says that's not an option that shows up. Any suggestions?Attachment 217928

[BetterRed]

The screenshot (Attachment 217928) doesn't exist.



BR

[Jaws]

1. Make sure that Daughter is signed in on the same account as was used to install Calibre.

2. Make sure that the account itself is an administrator account on that machine. That "install as administrator" is not showing up hints that this may not be the case.

3. Reboot, then try the install/update as the very first task.

4. Redownload the update, close the browser, then try the install/update as the very next task.

5. If there are games installed on the machine, disable Steam (known to cause almost-random permission and permission-like problems), then reboot, then try the install/update as the very first task, then reenable Steam.

6. If during any of the steps above, the install fails with an error 2502 or 2503, the problem is actually that the Windows Installer component has lost synchronization. To (about 95% of the time) fix this, open a command prompt with administrator permission, then type the following commands to force Windows Installer to reregister and resynchronize:
msiexec /unreg
msiexec /regserver
then reboot and go back to item 3.

If none of these work, it's also possible that there's a disk-space or disk-allocation problem and/or a bad download of the update.

[Sarmat89]

In the recent security update it was prohibited to execute the Windows Installer for non-administrators as a mitigation measure. The proper solution is promised soon.