"ERR:INVALID DIM" is an error message that comes up when one or more of the calculator's "STAT PLOTS" are set to "on" but there are no values or incomplete values in the "STAT" lists. It can also mean the user entered the wrong type of data.
If trying to make a scatter plot or attempting to do a regression, this error means that lists are turned on, but two lists do not have the same number of values. To fix the issue, hit the "Y=" button and complete the lists. This error can also show up when trying to input a list or matrix when the calculator expected a variable or number, or vice versa. To fix this, enter the correct input. This error can occur when using a TI-83, TI-84 Plus or TI-Nspire graphing calculator