Thanks! :D
Originally I was only going to have time limits, but then I saw how chill the game can be when you don't have one so I'm trying to make both approaches available :)
There is a popup when you first buy a mining charge telling you that they go in your storage and need to be put in your cargo to take them on a job, but I think this is very easily missed, especially since it will only show you it once. I'm thinking to have a popup let you choose whether to place it in cargo or storage, and then on the "job start confirmation" screen show you a little summary of the cargo you're taking with you.
Thanks for this crash report! I'll get it fixed ASAP!