Unable to access the Administrative interface of an application from APS Catalog as customer: 500 TypeError: Cannot read properties of null (reading 'length')

Gabriel Aznarez

Updated January 13, 2026 19:10

kb: bug kb: fixed

Symptoms

Unable to access the Administrative interface for applications installed from APS Catalog logged as customer:

PLESK_ERROR: Server Error
500 TypeError
Cannot read properties of null (reading 'length')
The same application Administrative interface is accessible when logged as server Administrator.

Cause

Product issue:

#PPPM-13842 "Customers can now access the administrative interface of applications installed via APS Catalog."
Fixed in:
- Plesk Obsidian 18.0.50 31 January 2023

Resolution

Please consider updating your server:

How to install Plesk updates

Workaround

If update is not possible for some reason you may try the following

workaround

Until the bug is fixed, navigate to the administrative interface URL manually and enter the credentials. e.g. for Joomla use "https://example.com/administrator"

More Information

Plesk Obsidian Change Log.