My backup jobs fail because Microsoft DPM is asking for a free tape.
The best way to resolve the problem is to provide Microsoft DPM with free tapes. With Firestreamer file media, it's easy to create as many tapes as needed. If you use drive media and want to increase utilization of virtual tapes, try enabling collocation of data in Microsoft DPM. You may also want to contact Microsoft Support for a professional advice tailored to your specific needs.