Tracker: create tracker modal not working when Category & PHP8.x

• Documentation (or Advocacy)

Solved - PHP 8 is not yet supported by Tiki and is planned to become supported in Tiki25.
Tiki22, Tiki23 and Tiki24 LTS require min and max version PHP7.4

When I run a new installation on a quite decent shared hosting (all-inkl.com) with PHP8.0 (or PHP8.1) and same time active feature Category, then it is not possible to create a new tracker.
The modal starts to open, but disappears before it is folded out.
For a glimpse of a second it is possible to see the title of the modal which includes an error message.
The error message is in red color as following:
Error loading content.

Either deactivating Category or switching PHP from 8.0 to 7.4 allows me create a new tracker.

Conclusion:
There is a bug affecting Trackers, that occurs in combination of active Category and PHP8.x

What I did:

1. test the bug in a show2 instance
result: bug not reproduced ... tracker created successfully

2. deactivate features on the devs local website step by step to find out the conflict
result: bug on local instance, not on show2.tiki.org, narrowed down to Category feature

❓ Think about possible differences of local instance and show2 instance ...
💡 Git vs SVN? http vs https? PHP version!

3. check PHP - local was on PHP8.0 - tried PHP7.4 and PHP8.1
result: the bug disappears, when I set another subdomain and run the very same website on PHP7.4 whilst the bug consists on PHP8.1.

Bug need to be fixed in PHP8.0+ , as 24.x is an LTS version.
Seems to be a conflict or a regression due to PHP version upgrade.

see: Requirements (mind to read the English page version, as other versions can be outdated)
PHP 8 is not yet supported by Tiki and is planned to become supported in Tiki25.

Thx to Marc to point me to this.

Use old PHP7.4 for the meantime ...

Use PHP7.4, which is required and recommended for Tiki22, Tiki23 and Tiki24 LTS .

This bug has been demonstrated on show2.tiki.org

Please demonstrate your bug on show2.tiki.org

This bug has been demonstrated on show.tikiwiki.org

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