Thanks, that's very helpful information, but shouldn't it be in the help? I tried searching for "Matrices do not conform to the operation" in the help (v9.2) and found nothing. I browsed and found a page which describes in general terms possible errors in IML but it does not contain the text of the error message so you can't search for it. This is my usual frustrating experience with SAS messages: they are not in the help.

Other software products I have used have catalogued ALL error messages by number and text and provided an entire book of explanations and tips about what to do. I find this very helpful. It should be done for all software: the programmers wrote the error messages so I assume they know what they mean.

SAS could improve the quality of its documentation by including the text of ALL error and warning messages with the sort of helpful information you have written in this blog. How do we get action on this?