AutoCAD 14 and Heap Errors

Factual Questions
1

Hi, long time lurker, first time poster here…

Has anyone out there had trouble with heap errors while using AutoCAD 14? We have some files that AutoCAD will not open, but kicks out what it calls a “heap error”. It is then nice enough to tell us that all our work up to this point can be saved, but AutoCAD is going to close. AutoDesk sez that it is due to lack of memory, but we just went to 733 Pentiums with 128 MB of RAM and a 20 GB hard drive, of which 2GB is used in the page file (we’re running NT 4.0), so memory is NOT an issue, but still we get these heap errors. Does anobody know a fix (or even a workaround) for this?

Thanks

2

I’m going to assume you’ve taken the obvious first steps and received the same errors. Like opening the file on different machines and attempting to open the file with the “Recover” command rather than a straight fileopen.

How big are the files? Do you have any third-party software that sits on top of AutoCAD? Can you e-mail one of them to me at rseaney@teamsigma.com without violating any confidentiality agreements? Have you manually modified the file “Acadr14.lsp?”

AutoCAD 14 works with its own internal memory paging as well as whatever the hell Windows does. Unfortunately, the manual controls on Acad’s memory pager are not as easy to use as they have been in previous releases, so … you might want to tak a look at the System Variables “Maxobjmem,” “Treemax,” and “Treedepth.” See also the AutoLISP command (vmon) for virtual function paging.

3

128 MB RAM isn’t a lot for AutoCAD.

How big are your files on disk? What’s in them (lots of polylines, text, …)?
What NT Service Pack? AutoCAD 14.0 or 14.01? What do you get when you type:

_vernum

at AutoCAD’s “Command:” prompt? In what version(s) of AutoCAD has this drawnig been edited?

Have you looked at ‘Heap error’ and Windows System Resources and AutoCAD?

Feel free to post questions at AutoCAD R14 Support Discussion Group (crummy Web intrface) or news://discussion.autodesk.com/autodesk.autocad.r14general (newsreader).

jrf
Member of the Autodesk Discussion Forum Moderator program

4

Our old fix for this used to be to open the drawing in R13, delete the old style logo (it was a block), purge the drawing, then reopen it in R14. But now we are getting the heap error on drawings created in R14, so opening in 13 is not an option. We have tried opening a drawing that throws the heap error from every machine in the group, to no avail. To answer questions raised above:

The files are usually 500KB or less, rarely climbing to 1MB. They are very simple drawings, lines, arcs, circles, etc. No polylines. “Recover” still throws the heap error, right after it finishes the recovery process. “Proprietary issues” prevent me from sending out the drawings–one engineer who thought it would be nifty to use MyDocs.com to store files for our vendors to use was flogged to death in the break room at the next coffee break.

No third-party software. This is a fresh installation of R14, so nobody should have had a chance to mess with Acadr14.lsp.

I typed in the variables UncleBeer mentioned and received the following:

New value for MAXOBJMEM <0>:
New value for TREEMAX <10000000>:
New value for TREEDEPTH <3020>:
–>If these are current values, I think (oh, no, the user thinks!) that MAXOBJMEM might be the source of our difficulties. Can you suggest some recommended values?

_vernum returns S.0.79

We are running AutoCAD 14.0 on NT4.0, SP5.

I have been to AutoDesk’s Heap Error page, and had written off all their suggested fixes but the last one. Now that we have brand new machines and all applications are at Installation 1.0, I thought I was able to write off option 5 as well. I had not seen the other file, but with a 2GB swap file, do you think that system resources could still be a problem?

I appreciate all help thus far.

5

By setting maxobjmem to some low values I have been able to force heap errors. You might wanna try starting AutoCAD, setting maxobjmem to something like 2.1 billion, which approaches the maximum value, and then opening your drawing. The problem with this solution is the maxobjmem variable isn’t saved anywhere. It holds its value only from session to session. You’d have to reset it everytime you restart Acad. Can you try this and let us know what, if anything, happens?

I really don’t know why you are having this problem, though. It appears to me you have sufficient system resources to handle much larger drawings than 1/2M.

I have another question, too. Have the drawings that are causing heap errors all been generated from a single machine, or from several different machines? If they’re only coming from one workstation, you may have a faulty Acad installation or even a corrupt Windows registry.

6

That’s 14.0; step one is to go to your dealer and get a free upgrade to 14.01 (your dealer is allowed to charge a small handling fee).

You can also try inserting the problem drawing into a fresh drawing. Sometimes that works.

Some more esoteric (and unlikely) fixes have been reported, but I suggest starting by upgrading.

7

The upgrade is a damned good idea, I wish I’d have thought of it. I believe Service Pack 6 is what we are running on our NT machines, too. You may also want to look at upgrading your OS.

8

Oh, and SP5 has been reported to be problematic; I would patch NT to SP 6a. Windows NT 4.0 Service Pack 6a

9

Well, we set MAXOBJMEM to 2.1 billion, and still got the heap error. I’ll talk to our sysadmin about both upgrades. We’ve actually been waffling back and forth about whether to upgrade all the way to 2000, but even that has been shown to throw heap errors. It looks pretty cool but there’s training time, etc., that we can’t really afford right now. We have another 128MB of RAM on order (IBM could not configure it that way off-the-shelf, so we ordered more and are running with what they sent us), so we’ll see what happens when that’s installed.

Some of these drawings were created on machines at our Swedish location, and some were created/edited here in Atlanta–I don’t think it was on only one computer. One thing I hadn’t thought of was that all the machines were installed from the same AutoCAD CD. I mean, we have enough licenses and all, but it was just easier to pop down the row with one CD, serial #, and auth code. I’m working out of my home for three weeks, but when I get back I think I’ll try installing from one of the other CD’s. I’m pretty sure, though, that we had this problem even when we had different copies on different machines (and running Win95 to boot).

Thanks again.