The version Modals 12.5.0Pro does not work. The popup window, which still opens in Modals 12.4.0Pro (see attachment login-popup.png), is no longer visible after updating to 12.5.0Pro, only the gray dimmed background.
The problem does not occur in Joomla 3.10.12. There Modals 12.5.0Pro works. The problem occurs in Joomla 4.3.3 and Joomla 4.3.4 - same site. If you reinstall the old version Modals 12.4.0Pro, it works again. It is not because of the override of the mod_login. The error also occurs when using the original Joomla mod_login.
Error reporting is set to maximum. I don't see any indication there.
I have created a copy of the site, Access data under Confidential
The version Modals-v12.6.0-dev2735116-PRO.zip gives the following error message:
Modals is not compatible with PHP 8.0.30 You need PHP 8.1 or higher to install and use this extension.
If I go from PHP 8.0.30 to PHP 8.1, then it works with Modals-v12.6.0-dev2735116-PRO.zip .
For this I get warnings at maximum error reporting elsewhere. The template is not yet released for PHP 8.1. But of course this is not your problem.
From my side the ticket can be closed. Thanks for the quick help.