Persistent "unknown exception" error appears after attempting to drag and drop events onto the timeline (Mac OSX)

Description: I get a persistent "unknown exception" error whenever I try to drag and drop events onto the timeline. This is on a Mac. I don't have the same issue running Voyant on a PC. 

This error does not occur on PCs. Even after leaving the Time screen and returning, the original event remains hovering over the timeline and I get the same error when trying to drag and drop other events. In other words, the lower panel of the Time screen appears to be frozen.  

Issue:  This error is caused by a screen redraw issue that is particular to Macs. The error will remain persistent on the Time screen until the software is closed and reopened. 

Solution: To avoid the error, try dragging the icon onto the timeline a bit more slowly. Don't release the click until a vertical placement line appears across the timeline below. Once the line appears you may move and drop the icon anywhere you like. 

If for some reason the vertical placement line does not appear, move the icon back onto the icon palette above, release the click and try dragging and dropping the icon again. Do not drop the icon over the timeline until the vertical placement line appears for if you do, this = persistent error will appear and you will ultimately need to close and reopen the software if you want to interact with the timeline.