You entered an argument with an inappropriate dimension. You entered a matrix or vector dimension less than 1 or greater than 255 or a non-integer. You attempted to invert a matrix that is not a square matrix.
If you can't figure it out from here, please reply to this post telling us what you were plotting or attempting to plot when you got this error.
Answers & Comments
From the manual:
You entered an argument with an inappropriate dimension.
You entered a matrix or vector dimension less than 1 or greater than 255 or a non-integer.
You attempted to invert a matrix that is not a square matrix.
If you can't figure it out from here, please reply to this post telling us what you were plotting or attempting to plot when you got this error.