Yeah, that's one thing I've noticed about Anaplan. Browsers all behave a little differently. Sorry you had that experience. You might still want to go ahead and let support@anaplan know about what happened so they can log it as a known issue. I'm sure others will face the same trial. Thanks for letting us know the outcome!
Yes @JaredDolich nailed it right on the head. Sometimes different browsers behave differently with regards to particular nuances in Anaplan!
Opinion: Chrome is generally my go to browser for Anaplan. Firefox works equally well. I have found Edge, Internet Explorer and Safari to have some quirks such as the error you faced. I know Anaplan will say these browsers are all generally supported.
There is one issue with Chrome for those that use the 90-trial workspace. Sometimes it won't open the model. I found that by using Chrome Incognito or using Edge, the problem goes away. Not sure why this is but it happens a lot.
From my time in Support I know that would be a browser cache/cookies issue most likely. Clearing cache/cookies, going Incognito, or trying another browser are all essentially doing the same thing which is starting a fresh Anaplan instance in a browser with fresh cache/cookies.
Yeah, it happens to me too because Master Anaplanners 1GB workspace share the same tenant as the 90-day trial (you'll get one too very soon!). We tried cache clearing and reinstalling Chrome but it didn't work. Something with Chrome. Not sure what though, we never resolved it. Keep in mind sometimes Chrome works, other days it doesn't. No pattern that I could see.
For example when I am working in an SSO enabled workspace and another that is not I generally open two different instances of Anaplan 1 in Chrome and 1 in Incognito. This is because there is a clash of authentication methods. So I log into 1 with SSO and the other through frontdoor.
I usually do the same when I am working in 2 different tenants at the same time. I will keep 1 tenant in 1 instance and the other in a 2nd instance.
Saved passwords I know also can contribute to this issue and same thing with accessing Anaplan through bookmarked Anaplan model URLs as the links might be outdated.