Cause of this problem: The given key was not present in the dictionary.
The error is pretty straightforward, you're missing a key from the dictionary. I'm sure what operations you're trying to process. (Delete/Access). What I'm guessing is that there's line like
PHP Code:
Dictionary.Remove(Key);
or
Value = Dictionary[Key];
what you need to do is to have a check before accesing the value such as:
PHP Code:
if(Dictionary.Contains(Key))
Dictionary.Remove(Key);