Help! Updated Studio 2021 and cannot enable any translation providers (TMs or NMT)

Hi,

I made the mistake of updating my Trados Studio 2021 at lunchtime. The first thing that stopped working was the DeepL plugin - so I downloaded the latest version but continued to get an error message telling me that I was attempting to load an unsigned plugin. When adding DeepL in project settings, I also get "one or more errors occurred". Unfortunately the same problem occurs with my TMs now, too: the "translation provider XXX could not be opened and has been disabled". I am now unable to work on any of my existing projects. Is there a way of uninstalling the update? I can work on a laptop (where I haven't yet installed the update) for the time being but really want to get back to using my main PC.