Already fixed for the next version. The bug only manifests if GLAS particles (and particles of a few other types of elements) are in non-zero pressure when saved, so the only solution is to save without pressure. I forgot how to do that, hold on, I'll look into the code.
EDIT: Okay, turns out the solution I was trying to remember only works when you stamp and copy. I'll make it work for full saves for the next version. In the meantime, I guess you'll have to pause the simulation and press '=' to completely reset pressure, and only save after that. :(
You're welcome! As a side note, I ironed out the handling of pressure inclusion in the UI so now it's just a checkbox in the settings dialog starting next version.