July 2018
11.1.0 is the latest update. One of your first Sims you would have to retire so you can have that party with a new Sim.
The game is essentially designed for you to retire Sims fairly often, it's sad to let them go. I had a hard time letting go of my Simself... But it's really cool to see where my Sims grand, grand, grand, grand, grand, grand, grand kids are now.
August 2018 - last edited August 2018 by EA_Jason
11.1.0 is not the new update they had two updates back to back witch cause a license revocation in the Canadian Store and I have people who work in not only the main Apple corporate office but owns an Apple and it’s confirmed they were revoked here.
*snip* I refuse to retire a sim to have a party this BBB is now involved due to 1. No party 2. Never got my grill in my inventory tho I have 100% evidence and 3. Can’t play due to no update and EA is not listening to Apple or me on how to correctly fix the issue. *snip*
EDIT by EA_Jason: Don't be rude
August 2018 - last edited August 2018 by EA_Jason
August 2018
The latest update for Apple is 11.1.0, for Android it's 11.1.1.
Android got another update to fix and issue when you used the back button when changing a Sims appearance. Apple devices don't have a back button so Apple didn't get that update.
Back to your original problem, this is the solution for many people:
https://answers.ea.com/t5/Bug-Reports/Cannot-Host-Party/m-p/6772800/highlight/true#M3171
I understand that you're attached to your current Sims, but The Sims Mobile, unlike The Sims 4 is designed to go through generations.
I don't have another option for you than that. So if you want to throw a party you'll have to retire a Sim. If you don't want to retire a Sim, you won't have the option for a party.
For the other problems you mention, please have a peek at the bug list:
https://answers.ea.com/t5/Bug-Reports/List-of-known-bugs/m-p/6682688#M633
If you don't see the issues you have on it, do make a new post as this one is about not being able to throw parties.
September 2018 - last edited September 2018
September 2018
Have you retired a sim yet? If not that’s why. I am level 45 had one party for the start intro after that zip because I refuse to retire my day 1 sims I am to attached.
September 2018
How many sim slots do you have and yes, your day 1 sim sadly. I retired one a few weeks ago still can’t do parties or anything. It’s their rules they told me on the phone!