Edit: I mixed up the versions below. This is now corrected.
I started my Grav instance with version 1.6.31 and I created a custom theme based on Quark 2.0.3. My custom theme extends some parts of Quark and includes a modular to display blog items on the main page. All worked fine until “recently”. After some updates, I’m now at Grav 1.7.17.
Now here is my issue. When I try to save my blog modular from the admin panel, I get an error:
Failed to save entry: Validation failed:
Invalid input in ‘Folder Name’"
Point is that I have no idea which “folder name” is meant by this. I already tried to strip the modular to its bare minimum, yet this did not help.
Any suggestion where to look or where to start is greatly appreciated!