FAQ | Why did my Crestron Q-SYS Module v4.2.1 stop working?

Learn why your Crestron Q-SYS Module may have stopped working and how to fix the issue.

Updated at May 23rd, 2023


Crestron released a July, 2020 update to some of their background usage of certain libraries, particularly related to JSON implementation. This update can disable modules built on older Crestron Databases. The Q-SYS module v4.2.1 is known to be affected, and ceases to work without some background recompiling. Older versions (v3.x, v2.x) may also be affected.

Be advised that the Crestron Application Market now includes a note for the Q-SYS v4.2.1 Module.


This module will only work with Crestron Device Database and earlier