Have a problem with a Word file in Studio 2015

I´m translating a specific Word file. After confirming some segments Studio 2015 freezes and does not response. The CPU load is very high, in the Task Manager I can see, that Word uses 10-15% CPU while Studio 2015 runs on 0-1%. When I stop this Word process with the Task manager, Studio starts to use 18-25% of the CPU resources, but it is still frozen and does not response. I can not confirm approx. 30% segments in this file.

I got this ready project from a customer. I also tried to create a new project on my machine, but the result is still the same.

With Studio 2014 no problem... Any Ideas?

My machine is a Dell laptop, CPU Intel i7, quadcore, 8 GB RAM.