New VHDX - stuck at 4096KB

Done this a bunch - never an issue. Environment is Hyper-V 2012 R2. I'm creating a new VM and setting up a new virtual disk using the new VM wizard. When it gets to creating the new VHDX it gets as far as 4096KB and seems to be stuck. I've let it run over night and still, stuck. I've tried creating a new VHDX on another hyper-v server and get the same problem.

Any ideas?

Thank you for the info. I was/am aware of that product and it probably would have solved my issue. I didn't end up using it. I found that the VHDX created at 4096KB was complete - but that for some reason the dialog box stating that it was creating the VHDX never closed. When I "cancelled" the dialog box the 4MB file was still present. Started the new VM and all was fine.