Hello all,
Composr CMS 10.0.34 was released early this week, and actually it updates the minimum PHP version to 5.3 (previously 5.1).
Yesterday, PHP 8 was released.
Anyone who tracks PHP versions knows that even 5.3 is a very ancient version of PHP at this point. On Monday, PHP 7.3 will be the oldest version of PHP supported directly by the PHP developers with security fixes.
We had to update our requirements because create_function was removed in PHP 8, and Tempcode relied on it. The 'new' alternative in PHP in anonymous functions, which came in PHP 5.3.
We should have made this clear with the 10.0.34 release, sorry for any confusion.
When Composr CMS 11 comes out, the minimum requirements are going to jump a long way forward, possibly to PHP 7.3, but it's not decided yet. Our previous thought process was to support all versions of PHP unless there was a strong argument that newer functionality would make our lives notably easier - for maximum compatibility. Our new thought process is that we should be a move our product forward so that PHP as an ecosystem isn't stuck in the past and so that users don't think it's okay to stay on old unsupported versions of PHP.
Updated minimum PHP requirement

Comments
Check the .htaccess file (which may be hidden in your file manager by default).
It could contain an override something like:
Code
AddHandler application/x-httpd-php52 .php .php5 .php4 .php3
Code
#AddHandler application/x-httpd-php52 .php .php5 .php4 .php3
I just helped a user identify this issue.