Missing Format Argument Exception

Hi there,

After publishing a minor update of my app in the Play Store (having used the nb184 version of App Inventor), I suddenly get reports by the Play Console of a certain "MissingFormatArgumentException" (see screenshot). It seems a variety of phones are affected as well as different Android versions.

I have no idea what that error means, and I'm pretty sure my update doesn't cause this since it's really minor. Also, I don't get any errors using the app on my phone (Samsung S8, Android 9).

Do you have any idea what problem I might have to look for? Or might that have to do with the reported problems in AI nb184?

The app is rather complex, so posting screenshots is difficult as I don't know what parts could be of interest after all.

Thanks for any help in advance

(The reports all look similar to this one with only some different line numbers.)