Problems after update

Hi,

I have just updated Piwik from 2.X to 3.3.0 and I encountered major problems.

Firstly, when I try to view my webpage statistics I get error “You can’t access this resource as it requires ‘view’ access for the website id = 1.” Everything except Piwik toolbars is blank.

Then, when I go to personal preferences, I get error “You must be logged in to access this functionality.”

And when I try to regenerate the API token I get error “Please specify a value for ‘userLogin’.”

Could anyone help me with that? I am by no means an IT expert. I am administrating my webpage which is on the external server.