Looks like we cannot reproduce this. Please provide another test case to reproduce this issue.
Error when linking a toolbar to viewport
Error: [ERROR][Ext.Container#setActiveItem] Setting activeItem to be a non-inner item
I realize my mistake, but I had to restart designer.
Could you post a step by step guide as to how you created this error?
I tried the following. Dragged out a Viewport, put a Toolbar in it.
Dragged out a Viewport. Dragged out a Toolbar as a top level instance, Dragged the Toolbar into the Viewport and selected "Link" when prompted.
Neither of these scenarios caused bugs/crashing issues for me.
Unable to verify this issue. Closing the ticket. Please ping us again if you are able to reproduce.