Following reports of gadgets being broken and javascript errors I have had to do some editing on enWS at https://en.wikisource.org/wiki/MediaWiki:Gadgets-definition and to note that I did similar at Meta.
I have basically made every gadget utilise ResourceLoader. Whether it is right or wrong, it has stopped the errors.
I am told that the OCR tool button and the horizontal layout button have disappeared, and I think that might be for the new toolbar, I have no issue in the old toolbar. More info will come if anything comes to light.
Regards, Billinghurst