I encountered this error while build a new project. I found the solution in a Chinese forum that's why I decided to share the solution here in english.
The ERROR prompt window is showing the message below. This happens every time I open the PCB Editor.
Unable to find the messaging system module definitions file 'allegro_smi_modules.txt'
ERROR: Could not initialize the Allegro error messaging system.
Solution:
Delete the $HOME\Appdata\Roaming\SPB_Data\pcbenv\env file
Try opening allegro PCB Editor again. ERROR should be fixed.
Comment below if this helps you in your troubleshooting.
Good luck!