Many music producers and other professionals prefer to use ASIO drivers to interact with their sound cards and other hardware devices.
While Mixlr does support ASIO input, we do not particularly recommend using it. This is because live broadcasting does not require the low latency that ASIO drivers provide.
Many ASIO drivers do not interact well with other software. This means some users experience problems opening their device using an ASIO driver. This can result in the error message you see above.
To fix this, we recommend you try an alternative input option. Mixlr is capable of opening most devices in either ASIO, or Windows’s standard audio drivers. You can also try closing other software which may be using the ASIO drivers, or investigate ways to use alternative drivers in other software.