Hi @GHES
I have a feeling these issues all revolve around the server running out of memory during either the load or save of the field.
Most likely, the flexible content field contains too much data, or the field names are too long for PHP to keep in memory during the page execution.
Please do check your server logs and maybe look into increasing PHP memory / max vars per page.
Good luck mate, I’m sure the issue will resolve itself with some simple investigating!
Cheers
E
