After upgrading the software I can no longer drag custom widgets from the canvas to my Widget Library with the widget library in Edit Mode.
I have found a work around by right clicking the item and selecting to add it to the widget library.
Unfortunately, I haven't been able to reproduce this issue. Could you please describe the steps you are following? Wich OS are you using? What kind of widget are you trying to drag? Are you working with a shared library?
Also, if possible, please send us a video/screen-shot. That would definitely help.
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