Created an account on Gemini - but can't seem to locate a link to create an issue...

I'm seeing this on a few more installs now. Installing a new copy of DNN 5.1.1 works fine, it seems to be the upgrades that are causing the issue.

The main issue is that even though the string isn't found in the resx, it returns Nothing, not even an empty string.

It's not fixed in 5.1.2.

Also, no custom local resource files can be read by the modules, even on FRESH installs of 5.1.1, also, it's not just that a null reference is returned because the key/value is not in the resource file, the keys ARE in the resource file.

This effectively means that any non standard dnn module from outside vendors will display no lables, help texts and throw null references because it can't read the resource files, and you also switched the behavior to returning null instead of unknown (which wouldnt be a problem if the modules could actually read the resource files!).