I keep having the same error on my three Wordpress sites. Whenever I click a link in one of them, I get the following error:
Using the FTP to download and examine the functions.php file, I notice that it is always deleted from a random line. (in the above example everything bellow line 54 was deleted).
I have used the backup / restore function to restore the sites, but after a couple of days, the same error happens.
Please advise on how to proceed, and thanks in advance for your help.