Her mummy never showed up and yes I have the latest patch and no I didn't lose my jars. Maybe when I get home from work tonight, I'll have her try to sleep in it and see if the mummy comes out. I even put together another sarcophagus to see if that one would work and I don't even get the option to summon a mummy on that one either.
Hi I'm new
Okay I had the same problem, and this is how I fixed it
I hope you didn't save after doing that, because it seems to be an odd bug that stays when you save AFTER activating it.
Anyways, I live on the beach and I was wondering if the mummy was showing up because of it that. So yeah, I experimented a lot and long story short, I built a basement, threw the Egyptian coffin thing into the basement. Also, I made sure that it wasn't against any walls, that it was in the center of the room because my Sim complained that something was blocking the path to it (strange). And yeah, a mummy appeared.
Note: I also had a total of 8 canopic jars and I put 3 in the house, so it had a total of 5 left, just in case it contributed to this odd bug.
You can tell if you're going to get the mummy to appear because your Sim literally opens the coffin thing and celestial light shimmers from within, and another household member slot opens up within a microsecond.
If anyone else hasn't come across the bug, then what basically happens is that you click on "Summon mummy" and your Sim walks up to it, and that's it. Nothing else happens. "Summon mummy" no longer appears. However, those 5 canopic jars remain in your inventory, however, you can no longer read the inscription. You can't even pick it up or move it out of your inventory. If you exit the game (after saving) came back in, then you can move it, sell it, whatever. But still, no more summoning. >.>