Why after enabling UnityIAP service I get an asset refresh loop in Unity and the project is unusable?

Hello

after enabling Unity IAP (and after installing some other unity assets as well) i get something like that in logs:

Refresh: elapses 0.308010 seconds
Unloading 14 Unused Serialized files (Serialized files now loaded: 0)
System memory in use before: 28.92 GB.
System memory in use after: 28.92 GB.

Unloading 15 unused Assets to reduce memory usage. Loaded Objects now: 6009.
Total: 11.665331 ms (FindLiveObjects: 0.761853 ms CreateObjectMapping: 0.300831 ms MarkObjects: 10.557432 ms  DeleteObjects: 0.042921 ms)

Refresh: detecting if any assets need to be imported or removed ...
Hashing assets ... 0.006 seconds
  file open: 0.000 seconds (2 files)
  file read: 0.000 seconds (0.001 MB)
  hash: 0.000 seconds
----- Compute hash(es) for 1 asset(s).
----- Asset named Assets/link.xml is skipped as no actual change.

Refresh: elapses 0.458680 seconds
Refresh: detecting if any assets need to be imported or removed ... Refresh: elapses 0.331798 seconds
Refresh: detecting if any assets need to be imported or removed ...
Hashing assets ... 0.000 seconds
  file open: 0.000 seconds (2 files)
  file read: 0.000 seconds (0.001 MB)
  hash: 0.000 seconds
----- Compute hash(es) for 1 asset(s).
----- Asset named Assets/link.xml is skipped as no actual change.

Refresh: elapses 0.277949 seconds
Unloading 14 Unused Serialized files (Serialized files now loaded: 0)
System memory in use before: 29.04 GB.
System memory in use after: 29.04 GB.

Unloading 15 unused Assets to reduce memory usage. Loaded Objects now: 6009.
Total: 7.593664 ms (FindLiveObjects: 0.853952 ms CreateObjectMapping: 0.341175 ms MarkObjects: 6.362604 ms  DeleteObjects: 0.033804 ms)

Refresh: detecting if any assets need to be imported or removed ...
Hashing assets ... 0.000 seconds
  file open: 0.000 seconds (2 files)
  file read: 0.000 seconds (0.001 MB)
  hash: 0.000 seconds
----- Compute hash(es) for 1 asset(s).
----- Asset named Assets/link.xml is skipped as no actual change.

Unity is unresponsive, it goes on and on until I kill it.

Afterwards, the project will not load, I have to reset the repository to open it up again.

This is the only thing I get when loading the project:

Refresh: detecting if any assets need to be imported or removed ...

We have this on two different machines, both with Unity 5.4 and Unity 2017.1.

What could cause this? How can I solve it?

Hi, do you have a Cross Platform Native Plugins by Voxel Busters?

If yes, please check the link below. It helped us.

http://www.voxelbusters.com/products/native-plugins/forum/index.php?p=/discussion/1487/resolving-packages-unity-not-responding