Wlanapi.dll errors are caused by situations that lead to the deletion or corruption of the wlanapi DLL file. In some cases, these errors can indicate a registry problem, a virus or malware issue, or even a hardware failure.

Follow these steps in the order they are listed below to address the most likely solutions first.

Recover wlanapi.dll from Recycle Bin. The simplest possible cause of a "missing" wlanapi.dll file is that you accidentally deleted it.

If you suspect this, but you've already emptied the Recycle Bin, you may be able to recover the file using a free file recovery program. However, only do this if you're certain the file was working properly when it was deleted (that is, it wasn't corrupt or malicious).