To enable logging :

  1. Navigate to admin screen, click on Logging and profiling section
  2. In the Class/Package name field type com.mxgraph, select ALL from the New Level combobox and click Add Entry


This setting will last until the server is restarted and must be re-applied after the restart.


To provide a browser console output: 

  1. Press F12 in your browser in the tab where draw.io is opened, then click on the Console.
  2. Right click on the console output, select Copy and paste the contents into a new file and save it.