(1) Yes, it is the only error message (there are three [unrelated?] warning messages).
(A) I have not looked at my app for a long time.
(B) I have never seen this message before.
(C) Because the app seemed to partially work despite this Chrome console error, I cleared the Chrome cache and browsing history, after which the app worked.
(It also works in the Opera and Microsoft Edge browsers - which I have never run the app in before).
(D) So it seems that even though I redeployed my app, partially and fully, to my server many times, something in the Chrome cache generated this error after a new version of AppStudio was made available.
I hope this makes sense to you and something has been learned from this problem, even if I myself have no idea what happened.
(2) Nevertheless, I now have an even larger problem:
When editing my app, 7 out of its 28 forms show up as blank with no labels, widgets, etc visible even though everything is listed in the “Project Explorer” window and clicking on them there shows their properties in the “Properties Window”.
But since I cannot see the labels etc, I cannot move them around etc…
(the other 21 forms are fine - I can see all of their labels etc perfectly)…
I will look to see if there is anything in the forum about this frustrating problem, and if I cannot solve it I will open a new topic ASAP.