[vBulletin 3.8.7] Post Editing and Quoting Problem

[rgxadmn]

Hello. I'm using licensed vBulletin 3.8.7 and I'm having a somewhat specific issue. I found the exact cause of the problem. However, I can't find a solution because I don't get any error messages. There is probably a simple solution but unfortunately I couldn't find it.

Problem: My members using Mozilla Firefox internet browser; When they say "edit" or "quote" to a message on any subject, there is no message content on the screen that opens. So, blank screen comes out. Therefore, they cannot edit and quote their messages. However, I'm using Google Chrome and I don't have this problem either in Chrome or in a different browser. My users who have the problem state that the problem is only in this forum, and in a forum using vBulletin 3, they do not have a problem with the Firefox browser.

The reason I identified: I recently migrated from a PHP5.3 hosting server to a PHP5.6 hosting server. This problem occurred after migration. It didn't exist before. So PHP5.6 might sound a bit high for vBulletin 3.8.7. But unfortunately there is no lower PHP version on this hosting server. Well; There is no version below 5.6 in the "Select PHP Versions" section. So I can't drop it. But I only get this error, no other error message or incompatibility. If I can solve this, we will be able to use stable.

When I scan the internet resources about the subject, I see that no solution has been presented. Only in 2017, someone on the webmaster forum with Turkish content named R10 experienced the problem and solved the problem by upgrading it to vBulletin version 3.8.11. But I'm so sorry; unfortunately my license only supports 3.8.7 at most. I can't upgrade. I need to find a solution to this problem without upgrading the version.

Can you help me please? Thank you.