What does this error code mean?

[SaintEaters]

Got to p3 at 30 something percent health left in Rancor raid and put it on auto so I did't run out of time. When my toons died it sat on the rancor screen for a bit then said error code 9.21, restart game. I didn't get any score for raid and hence no rewards. What does this error code mean. I took a screenshot of it, its attached to this post.

[EA_Andy]

Hey @SaintEaters

From that error it looks like connection to the internet may have been lost while it tried to record the progress of your attempt.

Is this something you keep seeing or was it just a once off?

- Andy -