The message; "An Unexpected error (170) Prevented Miscast sink from starting. please contact support with the error code." is a very common error, especially for users running Windows 10.
What is Error (170)?
Windows Error 170 means "The requested resource is in use". This implies that another software is using up the resources required for Miracast to run on AirServer.
The cause of the error message:
1. Another software such as Microsoft's "Connect" app, is currently using resources that are needed by AirServer's Miracast functionality.
2. The WiFi drivers are not up to date or in an inconsistent state.
How to resolve:
1. Turn off any other software that you suspect is using Miracast such as Microsoft's "Connect" app, then start up AirServer again. Now the error message should be gone and Miracast should be available.
If the above did not solve your issue, move on to step 2.
2. Download and install the latest updates for your WiFi adapter then restart the computer.