We started using Git LFS in a repository and didn't realise that Git LFS checkout / fetch wasn't something that happened automatically as part of "git checkout". So our binary assets didn't get converted from the Git LFS pointers to the real files, and when we built and packaged a release, we found that the assets were invalid (because they contained the pointer info instead of the actual file).
For now we can workaround the issue by adding "git lfs fetch && git lfs checkout" to our Harbormaster build plan after the working copy is obtained, but it'd be far better to have Drydock doing this so we're not running these commands for repositories that don't use Git LFS.