User has too many names in the blocked senders rule. Remove some, or all.
It’s very likely the user has been using Tools>Block sender on every spam he’s gotten. This is no way to block spam, as the sender name is different on almost every spam you receive. That means that there’s no point in adding a name to this list, because you aren’t going to receive email from that name again anyways.
Instead, you should set up spam filtering and blacklists at the server level.
Blocked senders should be reserved for very specific cases where a real person emails him repeatedly, and that email needs to be blocked for your big shot, but not for other people. (If it should be blocked for everyone then, again, do it at the server level.)
Curious which field or view might be a common denominator between these functions… (Adding to blocked sender list and Delete>Removing meeting request)?
I don’t know of anywhere that these two functions meet. However, the 32k limit on text fields is common. So, I’d say that this person is having the same error on two completely different problems.
For the remove meeting request, I’d take a look at the calendar of this person. Maybe they’ve got so many meeting documents that this function is bombing? Since you said you’ve got a test copy, try turning on the debugger and then doing the remove, and seeing what’s going on when the error pops up.
If none of that helps, I’d suggested a new posting where you out “error removing meeting request” in the title. You might catch the eye of someone who has had similar problems and may have better suggestions.