Maciej Kański

Please close Trados Studio, delete these folders, restart Trados Studio and then reinstall your apps using the integrated appstore:

c:\Users\[USERNAME]\AppData\Roaming\SDL\SDL Trados Studio\16\Plugins

c:\Users\[USERNAME]\AppData\Local\SDL\SDL Trados Studio\16\Plugins

c:\ProgramData\SDL\SDL Trados Studio\16\Plugins

But please make sure you ONLY click this button to install:

Maciej Kański

If that doesn't help then reset Studio.  

You could use this app for the reset and this will also explain what you will lose by carrying out a reset before you do it:

appstore.sdl.com/.../

But if you'd rather do this manually then rename this folder (just add _old to the end or something, it's not important what you rename it to) and restart Studio:

c:\Users\[USERNAME]\AppData\Roaming\SDL\SDL Trados Studio\Studio16

So the path would become this:

c:\Users\[USERNAME]\AppData\Roaming\SDL\SDL Trados Studio\Studio16_old

If you can't find this folder then you need to unhide your hidden files/folders:

www.howtogeek.com/.../

Many thanks Paul, the first solution worked.