So your memory cache is allowed to use 11097 MB because you set it to use that much via the Memory Cache slider, and Photo Mechanic is currently using 11,273 MB of your RAM. It will always use a bit more than your Memory Cache slider setting because that is only for stored thumbnails and previews, and the application itself needs to use some RAM as well. What is the indication of a memory leak?
How much space is available on the C drive?