[3.5.15] Error pages are unformatted, show raw stack trace only

[wsydney76]

Description

When there is a twig error in devMode, this error page shows up:

Steps to reproduce

1. Call a page containing a twig error, like {% set x = nonExistingVar %}

Additional info

• Craft version: 3.5.15
• PHP version: 7.4.7 (set to platform -> php -> 7.0 in composer.json)
• Database driver & version:
• Plugins & versions:

[brandonkelly]

Doh, thanks for reporting. Just released 3.5.15.1 with a fix. Due to a bug in the Updates utility you will need to update via the command line – see #7091 (comment).