Hi, I started writing out this question but solved it for myself. I'll anyway post this because I don't know why this error was happening.
This started happening yesterday, before that Trello used to work fine. I see an empty board if I try to 1) open a board or 2) open a card directly by its link as in the screenshot below:
I've tried 1) logging in and out of trello, 2) restarting my browser
Neither of these work. It works fine if I open it in another browser or open it in private mode.
If I opened my console, I could see an error which was like "DOM Quota has been exceeded" and other which went "localstorage isn't available". Unfortunately, I didn't take a screenshot before I fixed it.
The only difference between opening in a private window and my regular browser was the cookies and localstorage. So I decided to clear both and then logged in. This time it worked.
I suspect that the error might have been due to [not catching the exception which occurs after localstorage quota has been exceeded](https://stackoverflow.com/a/22412342/1412255). The dev team might be able to investigate further.
Thanks for highlighting this scenario and also providing the solution to mitigate the same.
It is interesting to know ,and am curious if there has been a recurrence ?