I was looking to extend the capability of this Grav by adding some extra Plugin's, but it did not go well.

Some plugin's are now showing their age, and haven't had changes in years, so adding can be hit and miss, or, as in my case, led to total failure.

Keeping track of changes should be second nature to an experienced IT individual, but sadly, is often overlooked.

Without access to the grav admin page, shell access can be used to disable the plugin manually. Find the impacted plugin's folder under the 'user/config/plugins' folder and edit the 'pluginname.yaml file', and change 'enabled: true' to 'enabled:false'

This should disable the plugin.

A more drastic approach is to delete the folder.

For one of the several plugins I tried out that failed, I checked the plugin home page and found a merge request that had the fix.

I have also managed to break Grav after upgrading due to default permission issues. Clues were found in the nginx logs, which pointed to write issues to grav/cache and grav/assets. Adding direcdtory write permissions for the group (www in my case), resolved the issue and normal service was resumed.