I've had this problem multiple times which is quite frustrating. Pardon me as I am a newbie to wordpress multisite. And I have tried almost every fix I've found online but this always happens. But everytime I back up my entire site on plesk, whenever I restore the back up, my site always comes up with the 'too many redirects' error. I have tried removing the plugins, copying in the original multisite enabled .htaccess file but nothing ever works unless I disable multisite by making it "false". Luckily, I haven't done much on the site so I just started again on both occasions but it is starting to get annoying. Isn't there a safe way to back up or to restore a multisite network without getting the too many redirects error. I consider myself a novice but I understand enough to make any necessary changes that are properly advised, someone please help?