Question: When I run my project on my iphone or in the simulator it works fine.

When I try to run it on an ipad I get the below error:

*file was built for arm64 which is not the architecture being linked (armv7)*

The devices it set to Universal.
Does anybody have an idea about what else I should check?

Answer: 
Just in case somebody has the same problem as me. Some of my target projects had different iOS Deployment target and that is why the linking failed. After moving them all to the same the problem was solved.
I should have added armv6 for iPad 2. Done that and it works now