JavaScript Exception

[martin-clarke]

I noted there were some previous problems with an error with JavaScript and widgets. (Back in 2016, with version 2015 I note)

However, I have just started receiving the following error:

JavaScript exception: Error calling selector function: Error: Invalid argument (also screenshot below)

I have no idea why this has just started (last published the site Friday last week).

There are no external widgets being used on the page, just a composition widget as a menu. It is only one page of this 'menu' which is causing this error.

[martin-clarke]

I note, that it doesn't seem to appear in Firefox. I only seem to be seeing this error in Microsoft Edge