FIX: DNSAPI.DLL is missing error
Some people have reported that they are receiving the error DNSAPI.DLL is missing since updating Windows. The true cause has yet to be found but we have read multiple online posts that Windows Defender might be causing this as its seeing an legit program as a false positive. We suggest you try and see if you have any quarantined items in Windows Defender and restore them.
Restoring Files from Windows Defender
1. Open Start and type Windows Defender, then choose Windows Defender
2. In Windows defender click on History
3. Make sure that Quarantined Items is selected.
4. In the list find and restore any file or registry item that was quarantined in October 2015.
We did read that rebooting your system might cause this problem to come back, repeat the steps above to solve it again. You could also consider using a third-party virus scanner to replace Windows Defender. Such as ESET, BitDefender or such programs.
The problem should now no longer appear. If it still does then please let us know. We are curious to know if this helped you solve your problems with Windows Defender.