CS4 error message: Could not read the file because the plug-in could not understand the file

Question

I get the error message in the subject line of this thread when I try to open a AI file in CS4. The file in question is a master plan for a river parkway. It includes a TIF of an aerial image of the project site (created from a SID file) with Illustrator generated linework for the various trails and other master plan features.  Illustrator attempts to open the file, which appears for a brief time but without the aerial image TIF background visible (only the Illustrator linework and text is visible), then this message pops up, I click OK and the file closes and I'm put back at the opening screen.
I am running Windows 7 Pro (32-bit). My colleague created this file on his computer (same OS and programs as my computer) and he can open it fine. He did have this same issue for a bit, but then ran Updates under the Help menu and this seems to have fixed his problem. Before then, he had been re-starting his computer and having only Illustrator open, and was successful in getting the file to open.
I ran the updates yesterday and am up to date but the problem persists.
Any ideas? Thanks.

Answer 1

Hi Sam,
This is an issue that has plagued Illustrator CS4 since it's release. The problem is a memory issue. Adobe has never addressed it satisfactorily and likely won't since CS5 has now been released for almost a year now - tho I've read somewhere that CS5 has the same issue. On their site, Adobe has made a few weak mentions about it and has posted a hit-or-miss workaround, but their explanation kinda sounds like B.S., really and it's fairly apparent they're not sure what's going on and likely it's a compound problem and the result of a few different issues. They talk about some bug with color books between Photoshop and Illustrator, but that's DEFINITELY NOT the whole problem.
Here's a solution, tho it's certainly not perfect and will not always work:
1. Start a clean instance of Illustrator - DO NOT LOAD ANY FILES EXCEPT YOUR TARGET FILE, and
DO NOT HAVE RUNNING OR LOAD ANY OTHER FILES DURING THE WORK SESSION.
2. Find a good free memory manager that will allow you to free up memory with the click of a button, such as CLEANMEM - Google it - it's free.
3. Free up memory before you start Illustrator and, if the file opens, after you get the file loaded.
4. While you'll be able to work with the file, save it; manipulate and create new vector objects within the file, likely you will not be able to add additional linked files.
In the past, the times that I've had this issue have been when working with really large files and large linked graphics - like convention display graphics. The issue just gobbles up, or limits memory allocation. Good Luck!