Indesign updated today to V.20 and.... these issues

I can't:

select multiple items with my cursor - I have to selet each individually 
select text certain text
copy and paste things (they paste on random other pages).

Any ideas? It's pretty disastrous for my current project.

It's become unusable, I'm considering ways to export the whole thing. Shame as I'd just set up a document and the update to Hide Pages is actually a great help. If only the rest worked.