In order to have aspx pages show their errors in a browser, you would need to add a web.config file to the application location (so /home/username/public_html/web.config file if the aspx page is in that location for mod_mono), then add the following content to that file:
mod_mono web.config
Code:
<!-- Web.Config Configuration File -->
<configuration>
<system.web>
<customErrors mode="Off" />
</system.web>
</configuration>
For Enkompass, the path will normally be C:\Users\cPanel\deathcal\public_html where C:\ is the drive location for the user.
Enkompass web.config
Code:
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<handlers accessPolicy="Read, Execute, Script" />
<defaultDocument>
<files>
<clear />
<add value="index.aspx" />
</files>
</defaultDocument>
</system.webServer>
<system.web>
<customErrors mode="Off" />
</system.web>
</configuration>
This shuts off custom errors and then outputs them into the browser to view for the failing page. For the Enkompass configuration, I also have it showing the defaultDocument (DirectoryIndex) as index.aspx for the site to set the main page.
Of note, if you have a failing aspx page for mod_mono, all pages on the site (even working test pages) will fail under mod_mono. So ensure to move the failing aspx page outside of the folder if you need other aspx pages on the site to function.