Lots of "semantic issues" causing build to fail?

Unity 5.1f1 Personal
Xcode 6.4
Target version 8.0
Build device version 8.3
Using plugins: Chartboost, iTween, had Unity Ads but tried to delete it by deleting the files

I tried to build on device to test Chartboost integration. Unity build went fine but in Xcode when I tried to run on the device the build failed with 17 errors. I have no idea what they mean or how to fix them. All the errors are in "Bulk_Generics_6.cpp" Here are some of the errors:

• Unknown type name 'DateTime_t330'; did you mean 'DateTime_t764'?

• Unknown type name 'InternalEnumerator_1_t3678'; did you mean 'InternalEnumerator_1_t3383'?

• Use of undeclared identifier 'Array_get_Length_m2497'; did you mean 'Array_get_Length_m1844'?

• Unknown type name 'InvalidOperationException_t1594'; did you mean 'InvalidOperationException_t1439'?

most of the others are just duplicates of these in different places in the same file.

Any ideas??