Thank you for the links to the screenshots you sent us and we were able to visualize the error.
Although we cannot tell you right away what are the exact reasons for this behaviour, it would be very helpful, if you could send us the entire Sitefinity2.6 folder that was created after installing our product.
This will enable us to test it here and observe the results. You can attach it after opening a new support ticket.
Thank you in advance for your cooperation and we are looking forward to your reply.