I discovered a bug and a work around for BlackInk Steam v0.225.1998 (D3D11). It tried to send a crash-report email through the bug-report dialog, but it said it couldn't connect to my email account (so that may involve another bug as well with multiple email accounts in Windows 7 Live Mail).
The Merge Down bug manifests on a multi-layer BlackInk file (I believe I had 6 layers in the file). I did a Merge Down from the layer tool bar for the top most layer into the layer directly below it. And then I saved the file. It crashed during the save creating an incomplete temp file that only had some of the layers (my original file was not damaged thankfully). I believe the error lies in the Merge Down code- it does not decrease the layer number variable that the save routine uses to encode the BlackInk file. I say this because my work around is to add another layer after doing a Merge Down and then deleting the new layer just added. This allows it to save without crashing.
If you need further details, let me know. Thanks.