Some users may experience the plugin failing to load in presentation mode, where you get this popup and it's unclickable:
A method has been found to resolve this issue:
This method appears to bypass the bug. We've reported this issue to Microsoft for a permanent solution.
This problem seems to occur when the add-in is inserted from the store into PowerPoint without being installed on your Microsoft account. If you encountered this bug, the add-in is probably missing from your account's add-in list.
When installed on your account, the add-in should function correctly in presentation mode: