Unable to post

Hi – apologies if this has been asked before. I can't seem to see a fix...

I have been using Express for just short of a year. I have been using it swapping back to the previous version as I couldn't get the update to work how I wanted it. I can't seem to work on tyhe older version any more, and now it says I can only post square format imagery – is this correct?

I just want to be able to repurpose older posts as well as new ones.

There have also been far more errors popping up in what used to be seemless scheduling. Please help, what am I missing?!