Thank you – I didn’t really want to disable Wordfence plugin, but it is the ‘obvious’ thing to try to exclude it from possible causes. Tried it with disabled and I still get the same error.
I shall have to dig around and find out how to check the Apache mod_security and PHP versions on both. I have previously copied from my TEST site to the LIVE site ok so I am thinking maybe one of them has updated since then….
