Problem with PHP 8

On the forum I read Tuan saying that Membership Pro is compatible with PHP 8.x. I have a development site with PHP 7.4 and everything works fine.
Locally, on XAMPP with PHP 8, I'm testing Membership and it doesn't work: as soon as I proceed with any save the invoice disappears, any Editor you use (both JCE and Code Mirror) and for different versions of PHP (use 8.0.1, 8.0.25 , the 8.1.12).
Is there a solution (otherwise I can't transfer to hos with PHP 8, in production)?
 

Here I am using PHP 8.1 in development and do not see the issue (and base on our report, there are other customers use PHP 8.1, too)

So maybe it causes by something else. If you can setup the site to a server which uses PHP 8, I will be happy to check

Regards,

Tuan

I'm also migrating from php 7.4 to 8.0. The issues revolve around what php modules are loaded. In my case I had to replace mysqli.so with nd_mysqli.so and add clos_ssa.so. This is all controlled by my hosting company and I don't know what XAMPP is loading. In Joomla's System Information there is a PHP Information tab that lists all the modules and parameters.

When things go wrong I'll get an error message in the system messages pane (determined by your Joomla template) or a long error message in the browser tab title (Firefox).

You can also create a file info.php that contains the line
<? phpinfo();?>

Just copy it to your site root to see what's loaded.

Thanks Hilmar for sharing your experience.