I was having the same issue with an OSD deployment.OnOptionalExecutionRequests failed for program * : 0x87d01106 logged. All references to the TS were showing their content status was good. I found this post and deleted a bunch of update ADR deployments. Suddenly the issue disappeared. Strange thing was, this didn't seem to affect my app deployments, only my OSD TS, and even then only the windows 7 ones, and even further, only when installing from software center, PXE worked fine. I don't know how I would have fixed if not for your post, thank you!