@babytes These are known issues. You can hit the 'me too' button here for both:
https://answers.ea.com/t5/Bug-Reports/OPEN-Sim-Can-t-Retire-LE-Generated/m-p/11668423/highlight/true#M221706
https://answers.ea.com/t5/Bug-Reports/OPEN-Sim-keeps-getting-Change-phone-color-action/m-p/11668807#M221195
If you're a mod user, you can try these mods to fix the issues:
https://littlemssam.tumblr.com/post/691130453403582465/new-random-bug-fix
https://www.patreon.com/posts/69721550
@ignominiusrex If you have Get Famous, check to see if the talent show is overlapping with prom. I've heard you can remove the talent show from the calendar when it pops up but another workaround is to change all lounge lot types.
@GalacticGal You can edit the auditorium where prom is held. I don't know if you're familiar with the Eco Lifestyle community lot but it works the same. Each event has a different phase of the lot you can edit such as career day, prom, and graduation. You can do this through manage world like any other lot.