Thanks for sending the error message:
Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function “my_forcelogin_bypass” not found or invalid function name […]
It appears your site is crashing because of your custom code.
The site can’t find the function named “my_forcelogin_bypass” which is an example function from the FAQ to showcase how to add exceptions to Force Login. I suspect your site has the following custom code added someplace which isn’t working:
add_filter( 'v_forcelogin_bypass', 'my_forcelogin_bypass', 10, 2 );
You need to either remove that line of code from your site, or fix the function name it references to an existing function.
I recommend you hire a web developer to help you customize this for your site.
Thanks!