Presumably after an update to GNOME Shell, 'Put Windows' extension stopped working.
This was only discovered after trying to put a window into a corner (upper leftmost) of the screen using Super+7 (numeric keypad). The GNOME Shell Extension website – Installed extensions showed ERROR in the place where the extension is turned ON or OFF.
How can I fix this issue?
This was reported on the GNOME website with a support ticket and has been resolved.
Best Answer
After reporting the problem I got the following response from Gnome which has SOLVED the issue:
"Version 27 is now inactive and v26 is the most current version. Please check, that you are using v26"
So, I restarted gnome with AltF2r and then selected 3.26 as the Extension version to reinstall it.
The extension now works again as it should.