Hello:
I deactivated the plugin for a moment and, when I tried to activate it again, it told me: "The plugin could not be activated because it caused a fatal error." I deleted it, re-uploaded the .zip file, both version 1.7.8 and version 1.8.4, and the error still persists. What could be the problem?

Hello,

Could you check PHP error log to understand what error occur? What WordPress/PHP versions are used on your site?

Regards,
ARI Soft

WordPress version: 6.4.2
PHP version: 8.2.13

I already tried versions 7.4, 8.0. 8.1 and the error persists.

I attach error_log. I don't understand much about the subject.

Thank you in advance.

We don't see any errors related to "ARI Stream Quiz" plugin, but it contains a lot of "WordPress database error Commands out of sync" for posts table. Probably something is corrupted in database. Does installation problem exist only with "ARI Stream Quiz" plugin or other plugins also cause this problem?

PS: We can investigate the problem in more details if you provide a temporary access to your WordPress admin part by email.

Regards,
ARI Soft

Thanks for your help. I changed the cache plugin for another one, then I deactivated all the plugins and I activated Ari Stream Quiz first and that's how it worked.