Cannot post, but no errors

Hello,
My wordpress installation today have some problems.

I’m triyng to post, but I don’t know why, I can’t….

If I click “add new” the edit post page is opened, then if I click “publish” or “preview” or “save draft” I’m returned to the post list page, and no errors are displayed.

Even if I try to upload to the media gallery, here the file if phisically uploaded, but don’t appear in the list, so seems to be a database “write” problem.

How and what can I check to have all working?

Thank you so much