can't log in (don't have sufficient permissions error)

All of the sudden, I can’t log into wordpress. I get the error “You do not have sufficient permissions to access this page.”

I can, however, click on the lost password link and reset my password to get in, but as soon as I log out again, I get the same error. This is pretty inconvenient and I can’t seem to find any info on how to fix this.

Hoping someone can help me!