Hello Claes,

Thanks for reaching out to us. Could you please share temporary administrator access to your Joomla backend? You can provide the credentials securely in the hidden content section. Also, please take a full backup of your site before we make any changes.

Once I have access, I’ll investigate further and see what’s causing the issue. Let me know once you’ve shared the details!

Best Regards,

Problem solved

Due to the log something trigged the ModSecurity-rule:

https://oxxo.nu/administrator/index.php?option=com_ajax&helix=ultimate&id=12

Something with "Pattern match "^([0-9a-zA-Z+/]{4})+([0-9a-zA-Z+/]{3}=)?([0-9a-zA-Z+/]{2}==)?$" at ARGS:comment.".

This rule comes from Hostdime

Could it be a clue for your team? //Claes

Thanks, We will check it.

Best Regards,