The initially released version of SketchUp 2014 for PCs, was found to have an issue if the SKP was opened from a drive which wasn't the same [system] drive on which SketchUp.exe and its related Tools folder was installed. It also unexpectedly had other issues with reading Plugins folders when there were accented characters or single quotes in your User name.
A new updated version is available from the Trimble download site - it addresses those issues.
So if you get/install that and still have these problems then maybe we need to look deeper...