I used the Sketchup export plugin and it ran successfully. The dialogue at the end notified me that 2,952 items had been successfully exported. The ruby console and the log files confirmed that everything had been exported successfully. I then imported the FBX files into Unreal and ran the UE4 plugin and it notified me that I was missing an FBX file. After some examination I found I had 2,950 FBX files, and 2,952 DAE files - meaning two of my DAE files had not successfully converted to DAE.