Taking the El Fuego to the Temple of Sirius mission in the attached save causes a crash with the error message "no xcom units could be placed on the map".
Removing the custom unit deployment on the El Fuego (by removing and adding a unit in the crew select screen so that the Preview* button becomes Preview) seemed to "fix" the crash.
A custom unit deployment that is just a copy of the default deployment also crashes, so I do not think the actual placement of the units is the cause of the issue.
Some people in the Xpiratez bug report chat room reported that they were NOT able to reproduce the issue with the provided save. I downloaded a fresh copy of the latest Xpiratez (vN1.1) and was still able to reproduce the issue myself, so I don't believe any of my settings or file corruption is to blame.
I'll be happy to provide any other info or help with testing if needed
I had the same issue but was sending 2 Gnomes to the Highway Star bike mission underwater with a Blowfish.