Internal Error

After adding class parameter overrides (23 overrides), when trying to either add another or editing a current override I got the following error:
Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

I cannot add nor edit any override for this particular class parameter.
Expected outcome:
Foreman should create or edit the class parameter.

Foreman and Proxy versions:
Foreman: 1.12.4
Postgres: 11.2
PhusionPassenger: 4.0.18

Foreman 1.12 is very old and no longer supported. The currently supported versions are 1.24 and 2.0.
It is very likely this issue has been fixed in the 3.5 years since 1.12.4 was released. I would highly recommend upgrading to a newer, supported version.

Unfortunately upgrading is not possible at this time.
Seems that the only way to do any modification is by deleting a few matches and disabling the override. Then reopen and add as needed.
The steps are as follows:

  1. Open the desired class parameter.
  2. Remove one/two/n match(es).
  3. Uncheck the override checkbox.
  4. Click submit button.
  5. Open the class parameter again and check the override checkbox.
  6. Now you can edit or add a few more (until reaching 23).

It is fairly unlikely anyone has a working 1.12 and can help you debug this issue. Considering this hasn’t been reported by anyone else in the past several years, even if someone does debug it, the solution will more likely than not be to upgrade to a newer Foreman that doesn’t have this issue.