Problem identifying room

[tsUmOmO]

Hi,

I have IES VE 2014 for Engineers with a student license. I installed the plugin on Sketchup 2015 but can't identify the rooms even in a very simple showbox model. I get the following message when trying to do so:

Exception: undefined method `-' for nil:NilClass

and then a list of files of the plugin folder. I've tried restoring the installation but didn't work. I also tried making groups and in this case the message was different. Just a normal message from the plugin giving the likely causes why the rooms were not identified (like having components or thick walls, which is not the case), but still couldn't identify them.

What could be the problem here?

Thank you,
Inés