wsrevtheme

OK, the issue has been resolved and it was to do with the host. The ftp upload quota had been reached and somehow this prevented the WordPress files from being updated properly. Increasing the ftp upload quota resolved the issue. Hopefully this helps someone.

I have the same problem – every time I edit code in the theme editor the whole php file becomes blank. Once this happens it is impossible to re-add content to that file, as each time I hit ‘update file’ the file becomes blank again. The files I have not edited are OK.
This has only happened recently and I have updated these files many times before without issue. I have not upgraded my WordPress version or changed theme recently, and as far as I know I have not made any recent changes that might have caused this. I have the same problem on multiple sites. If anyone knows a solution for this, please let me know.
Thanks