Hello Derek,
Thank you for sharing the project.
It seems that the information in orthomosaic.zip/doc.xml file is corrupted. You should remove <mask>...</mask> section from the file, as it is not pointing to the file, but to the directory. The issue appears to be related to the stand-alone module usage only (during the project generation).
We'll try to fix it as soon as possible, meanwhile the only solution seems to be manual fixing of the doc.xml for the orthomosaic.