Empty page in custom theme after Upgrade to PHP 8, no errors logged

[phae]

Hello,

I've been in the process of adapting a custom theme for the latest InvisionCommunity 4.7.6. and PHP 8. It worked well with 4.7.2 and PHP 7.4,  Since I hav disabled some incompatible plugins and updated a few custom blocks, it started working with the upgrade - but *only* in designer mode. Without theme designer mode I just see a blank page and no errors in the system log, the error log or my php error log. Some subpages also work without designer mode, but my start page and a few others do not.

I've synced my theme changes when disabling designer mode, cleared caches and made sure my php settings are working by temporarily adding error_log("Test") to index.php.

Any hints on how to investigate, debug this further? I except some of my templates or blocks to need an update, but I'd except to get some form of error or exception if the whole board fails to load.

thanks for your time

[Randy Calvert]

You can try turning off suppression of PHP errors to see what PHP is specifically choking up on. 

Try adding something like the following to your htaccess:

php_flag display_startup_errors on
php_flag display_errors on
php_flag html_errors on

[phae]

Thanks for your answer, @Randy Calvert. Forgot to mention it, but according to "/admin/?app=core&module=support&controller=phpinfo" all 3 of those settings are already in effect. Something still seems to suppress my errors

[Marc]

Have you cleared cache from the support area? Also, are you using disk template caching? If so, try switching that off.

It should be noted, you should never use designer or developer mode on a live site

[phae]

Hi @Marc Stridgen - Yes, I've cleared system caches from the support area multiple times. And disk template changing is turned off.

[Marc]

You would then need to check with your hosting company to see what is suppressing errors on your server. 

[phae]

As stated, if i add

error_log("Test");

to my invisioncommunities index.php, that line shows up in the error log just fine, so unless I am misunderstanding you, it seems like PHP errors aren't suppressed per se?

(I am running the host myself)

Edited January 26, 2023 by phae
clarification regarding the hosting company

[phae]

Sorry, you are right. error_log is logged, but syntax errors are not for some reasons. Will post again when i found a solution.

[phae]

Not sure what exactly happened here, but setting `DEBUG_TEMPLATES` in constants.php to true helped me to get an error message and for my templates.

[Marc]

Glad to hear you got the problem resolved there 🙂