Can't go into preview mode

I can’t seem to go into the preview mode for whatever reason and see how my page would look like on the internet. I had RapidWeaver Version: 5.3.2 (11606) and the pop the window pop up used to say :

-[WebFramePrivate path]: unrecognized selector sent to instance 0xc4ec210

Then I upgraded to RapidWeaver 6 hoping that it would fix the problem but I still can’t get into the preview mode. There used to be a pop up window saying : -[__NSDictionaryI path]: unrecognized selector sent to instance 0x7fb19501a470

But now, anytime I try to click on the preview mode, the program just crashes.

Any ideas on how I could fix my problem?

Thank you!

System Version: Version 10.10.4
Hardware: 21,5 inch iMac, 2.7GHz Processor, 8GB Memory.

Could you drop us a note: We’d need a copy of the project file to take a look at this!