AutoCAD LT 2018 FATAL ERROR: Cannot write to undo file probably disk full

[Anonymous]

while i'm working on AutoCAD LT 2018 on my Mac, with no particular reason this error shows up (FATAL ERROR:cannot write to undo file probably disk full).

So i've looked for solutions in this forum and i found something like empty the temp folder or disable the undo command. I tried to empty the temp folder and even then i still get the same error. i don't want to disable the undo command because i think it would be annoying to work without it.

I even read about some pan/zoom issues about this problem, i combined it by doing Undo-> Control->Combine->Yes and but it's not working either.

Is there really a solution for this error or do i just have to live with it? is there a setting to remove pan/zoom fro the undo command? anyone else have this problem?

Thanks for the support.

[maxim_k]

Welcome to Autodesk Forums!

Hi Andrea,

Let's start with checking how much free disk space is available on your Mac. Can you check this by using "Get info" on your Mac drive?

If you have enough free disk space, then another question:
where are the drawings you open in AutoCAD located? Local drive, network drive?

Maxim

[Anonymous]

Hi Maxim, thanks for replying

i do have a lot of free space on my disk (right now i'm using 100GB out of 1TB).

The drawings that i use are both in my local drive and in the network drive. it doesn't seem to make a difference.

My temp folder is completely empty.

thanks again.

[maxim_k · Accepted solution]

Have you tried to restart AutoCAD - use QUIT command to close it completely, then launch again?

Have you tried to Reset AutoCAD? To reset it use Menu AutoCAD -> Reset AutoCAD.

Maxim

[wei503]

Hi @Anonymous,

Can you please send out a crash report and let me know the report ID? THe ID shows in the pop up browser page after you send out the report, it looks like this: CER_xxxxxxxxx.

Thanks,
Wei

[Anonymous]

i'll do it the next time the problem pops up again... i already sent an e-mail to the support,i can give you my case number if it can help...

[Anonymous]

will the reset command delete all of my settings on AutoCAD? (like palettes,proprerties window etc..) 

i've done the quit command now. i'll let you know if this procedure worked somehow.

[maxim_k]

>>>will the reset command delete all of my settings on AutoCAD

Yes, it will. That's why I asked you restart AutoCAD at first.

Maxim

[Anonymous]

as i said before, i restarted AutoCAD. now it's working normally but i guess i have to wait a little longer and see what happens to consider this problem solved.

[maxim_k]

OK, let us know how it will go.

Maxim

[Anonymous]

I have the same problem. Just sent an error report.

[Anonymous]

 well, it happened one more time. this time AutoCAD crashed while i was saving (literally press cmd+s) and it stopped working. It didn't open the "fatal error" window so i don't know if this two problem are related.

Anyway this is the ID you asked me.

CER_166454565 

[Anonymous]

The Autodesk support contacted me and via TeamViewer they checked on my Cad doing some tests... 

The problem in my case is my saving format. I used to save my file in AutoCad 2007 to allow almost everyone to open my files (not everyone has Autocad 2018), so the support told me that saving in 2007 creates some big files in the UNDO.ac$ directory and that's why it crashed a lot. 

He even said that he will inform the developers about this problem.

I hope this will be helpful for other customers.

[Anonymous]

Posting the actual response of the support.

"As tested, the reported behaviour appears to be caused be the file format DWG 2007, which creates a large UNDO/REDO file when working or while saving the drawing.

To avoid this behaviour please consider to use a newer file format (e.g. DWG 2018) while working on existing drawings. If you need to exchange drawings with customers that use an earlier release of AutoCAD, you could down-save the drawing to the desired file format, before sending it to the customer."

[maxim_k]

May I ask you:
How long are you working on one average drawing without closing it in AutoCAD? Some hours? A day? Several days?

Maxim

[Anonymous]

I'm getting this regularly. It's becoming rather tiresome.

Normally it happens about once a week but it's happened twice in a day today and I've lost too much work to ignore it now.
I've got 268gb out of 1tb free so it's nothing to do with storage.
I've tried quitting the program to no avail. Worried about what a full reset will do - will that definitely work and if it does, what will I lose?

[wei503]

Hi @Anonymous，

Please let me know the version of AutoCAD LT from menu AutoCAD LT 2018> About AutoCAD LT. I need to know if you have all updates installed.

And do you use any clean Mac tools?

Thanks,
Wei

[Anonymous]

Hi, 

responding to  @Jorfeur and @wei503, in fact i'm using a clean tool (Dr. Cleaner) and it looks like if you clean the memory by using the cleaner it will sometimes make AutoCad crash.

Anyway after the support contacted me and explained what was the problem in my case, the crashes occur way less often, i would say they pretty much disappeared.

So i recommend @Anonymous to contact the support and let them have tests and see what's "wrong" whit your AutoCad.

Responding to @maxim_k, i work on it some hours a day, like from 2 to 6 hours a day. as i said before the crashes in my case tend to happen when i clean the memory while using AutoCad or when i've been working on the same file for a long time (like 4 hours) sometimes leaving it open and letting the mac go in standby mode.

Anyway the problem seems to be 90% solved to me, so i hope this post will help someone else fixing their problems.

Thanks for the support.

[Anonymous]

The version I'm using is O.48.M.478  -  2018.1

I don't use any disc cleaning utilities.

[Anonymous]

Would it help if I sent you the crash report?