Mine does it, as well. I'm using 28.0.

Olivia, can you tell the exact details of the setup you have?
The OS version, what gets lost exactly on launch (all of the preferences or only some?), are you the only users with the administrator’s permissions or is it a somewhat different situation?
The same exact thing happens for me but with the latest Beta only — can you check it as well?

Same Problem, Version 28.1, User Preferences reset to default every time I open the program.

Same issue here , and not all preferences are reset on opening, in my case just the Units under General which change constantly to points instead of mm. It is not the first time either. It's happened with past versions of ai at least 3 or 4 times. Somehow at some point with one update or the other the issue disappeared on its own.

Same problem + the colour settings are resetting too.

Every time I open Illustrator the units in preferences revert to pixels instead of inches. Very annoying!

Have the same issue here. Is there still no solution for this problem? Win10 Pro Illustrator ver. 24.3 64bit

I'm having the exact same issue as well! It literally resets itself to the default settings everytime I close the app. Is there a fix to this?

I'm having the same sort of problem as well. I'm using a iMac running OS Catalina 10.15.6. Every time I open AI, the units revert to points instead of inches. Is there a way to lock this? The rest of the stuff I can deal with, but this drives me crazy. I've been using AI since the 1980s and it has improved steadily over the years, but little things like this shouldn't be an issue.

Same problems here. Windows 10 machine.

July 22, 2020. Same thing happening here. I'm using CC and AI is up to date. I just got a new Macbook Pro running 10.15.6; this wasn't happening on my old computer as of last week (same OS, same up-to-date AI software), for comparison's sake. Hope they find the fix soon.

It's July 2020 and every time I open Illustrator 2020 it welcomes me and loses all my preferences. It's really annoying so I will just continue to use 2019.

Felt validated searching Google and finding this thread with so many people experiencing the same thing (since 2018 no less)

My suggestion to everyone here is to get your workspace exactly how you want it, then click "New Workspace" and hopefully, that will at the very least shorten the time it takes you to set up your work flow again.

I'm having the same issue where, when my computer restarts, it reverts to "Essentials" - this way, I don't have to manipulate any existing workspace.

I have the same issue. Extremely annoying and a huge waste of time every time I restart my computer.

+1 I am experiencing this behaviour on 2020, 2 different pcs, both win10

I have this problem on both Mac & Windows Illustrator v23 2019, preferences will not save as every time I reopen the application preferences are reset to default....very annoying.

it works fine but if i turn off my Laptop then turn it on and start illustrator then its settings are rest completely.

Glad I finally found this comment section, but very, VERY disappointed at the fact that so many are having my exact same issues with Illustrator CC 2020. I spend way too much of my time dealing with these issues that it has put a big strain on my productivity. I don't know if any others experience this either, but I also have issues with my Mac shutting down all the time if I have both Photoshop and Illustrator open at the same time. And it's almost a given that if connected to Safari or any other, my machine will most certainly shut down and restart. I'm losing precious work time because of all these issues. I've always been a huge Mac fan but this is just plain unacceptable, especially since, as someone wrote in a previous comment, now we pay monthly fees, and not small. Very, VERY unhappy customer here.

Baloney, it is a generic issue, because I have it all the time and I'm sure many others do too. Very disappointed there is no answer here.

i have contacted adobe multiple time about this an all they do is waste time look at you computer to and are like ok its fixed it should never happen again for it to happen 5mins after you get off the chat with them.

CC is so full of bugs that will never get fix because "this is not a generic issue that we can reproduce on our end"... which they say for every issue and to never have a fix yet there are so many trends and post about these issues

It is unacceptable to be the leading software in the industry and never fix a **** thing while we now have to pay monthly for a product full of bugs.

pro tip : make sure your product works before you release it...