Hello fpwong,
I’m one of the creators of Iliad : ILIAD - Paint and draw on Unreal Engine - Beta version in Code Plugins - UE Marketplace
Usually creating my Brush Blueprints with the help of Blueprint Assist and AutoSize Comment.
So far so good 
However, it seems there is a conflict between our plugins, especially when someone wants to paint in the Viewport, using Iliad :
error_report.txt (8.7 KB)
(everything called Odyssey here is related to Iliad)
Here are the steps to reproduce :
1- install Iliad from the marketplace and create a new project
2- add a cube in the viewport
3- create a new texture in the content-browser (right click > Iliad > Texture)
4- drag’n drop the texture on the cube
5- select “Iliad mode” at the bottom of the screen
6- try to paint on the cube (also crash when you paint with a mouse)
The first lines of the crash report are “Blueprint Assist ToolBar” related.
Can you let me know more about whats going on ?
There might be a problem on our side too as we have also a toolbar in Iliad. Maybe some kind of conflict.