(Not a bug) Garbled page output with PHP 7.4 (zlib extension is required)
On my local testing server, with XF2.1 and VW4.1.0 b001, changing to PHP 7.4 causes wiki page output to either be garbled or for placeholder text to be shown. Changing back to PHP 7.3 resolves this issue.
The garbled text seems to be limited to one Area, although the size of the wiki on my local test server is very small. This area only contains regular pages and templates. Both of those content types are affected + the Area main page. If it helps, I can create other content type pages.
I was able to create a new wiki page under PHP 7.4 and the page output is correct this time. Further revisions with PHP 7.4 are also fine. However, if I change my testing server back to PHP 7.3 and then edit the same wiki page, changing forward to PHP 7.4 will once more result in unexpected placeholder or garbled text when viewing the same wiki page.
Trying to compare two revisions displays an error: "Error: Content uses an unsupported type of compression."
There are no entries in the XenForo admin cp server error log.
Two PHP 7.3 vs 7.4 comparison screenshots have been attached to this issue