Status code 403

I'm using RStudio Cloud for one of my courses this term, and my students and I have encountered an increasing number of "Status Code 403" errors. If the student leaves the project (say, to the group page) and then returns, it goes away for a little while, but then can return within 5 minutes or so, which is very disruptive. Any tips on why this might be happening or how to prevent it would be much appreciated!`

We recently pushed out a newer version of RSP, so it is possible that is the cause of the issue.
How long from initial opening/creation of the project until the error, would you say?
Would you be able to take a screenshot of the error to share here as well?

It takes a highly variable amount of time. Sometimes the project works for a while then the error message appears, and sometimes (like today on project Posit Cloud) it shows up right away. One of my students reported getting the error message about 5 minutes after opening his project every time he opened it, so he could only do about 5 minutes of work at a time (and he tested multiple web browsers and found the same every time).
The error message takes different forms. Sometimes in a pop-up:

And sometimes in the console:

I think one student also had it showing up

It sounds like there might be a couple different things going on here:

First, There is a known issue that causes this error message when you leave a tab running but do not interact with it for some period of time. We haven't exactly identified how long it takes for this to occur, but some of our testing showed it could happen after as little as 15 minutes of inactivity. We're looking at possible fixes for this issue, but refreshing the browser should be enough to fix it in the meantime.

Secondly, it's possible some other types of problems could cause this error message. For example running R code that exhaust the memory on the system (causing the IDE to crash). Do you happen to know if the student was running code that could cause this type of error?

It's good to know about the issue with inactivity.

I don't imagine that the student's code would exhaust the memory on the system. We're just running basic descriptive statistics (mean, histograms, boxplots), and then using the t.test command. I wouldn't expect those things to use too much memory.