I am trying to install a custom theme plugin, i come across this page
I click on upgrade moodle database now but i come across this error
There isn't a version of the Rocket theme compatible with Moodle 3.1. The last version *might* be compatible with 3.1 but it might not (it's clearly not been tested).
It seems like a strange problem to be caused by a new theme but it's not completely impossible.
The same issue is occuring with Adaptable theme which shows to be compatible with moodle version 3.1