I am unable to use activities in UiPath community edition tool after new Version 2019.5.0 update.
Workaround:
I have uninstall the UiPath tool. And installed again, same error occurs. The errors comes even though i have installed all recommended packages.
Go to Help section and check whether you are using Stable or Beta channel. If it is Stable then update to Beta channel and restart UIpath once and give it a try.