My 4.3.3 install is not generating post ids

Hi
My 4.3.3 installation is broken. I am unable to add new pages and also cannot add new images to the media library.

I first noticed it with the images because they would be uploaded and saved in the correct folder in the file system, but the wp_post entry in the database has no id. The id is zero.

With the pages I get message ‘You are not allowed to edit this post.’. I think this is part of the same problem, i.e. that my installation is no longer able to generate ids.

I upgraded to 4.4.2 but did not fix the problem.

Any pointers would be much appreciated.
Thank you