Basically, it's saying that there is a problem, probably with your RAISERROR statement.
MSG 50000 is reserved - the system generates this when msg_str is specified.
Level 16 is the severity - as a user, you can generate any severity between 0 and 18
State 0 is a number that can optionally be used to identify what part of a large query produced the error.
Line 10 is the line number on the input query at which SQL noticed the problem (this doesn't mean it is on line 10, but it'll be not far off).
See the MSDN for
RAISERROR[
^]
Without seeing your code that threw the exception, we can't help much more, but look closely at your RAISERROR statement - it looks like you have a small error in it.
Thinking about it, I know what your code looks like:
RAISERROR('Divide by zero error encountered', 16, 0)
And I would expect to get what you did from it:
Msg 50000, Level 16, State 0, Line 4
Divide by zero error encountered