10.13.1 and having the problem saving to internal MacBook pro drive.

just updated Mac OS and I have had the problem continuously since then, just saving to my hard drive. SUPER ANNOYING!

Same problem as Evelyn: After upgrading to High Sierra and the latest Adobe updates. I am saving to my internal SSD drive (with Time Machine backups to an external WD drive). I also longer have thumbnail images for InDesign, which I updated on 11/17/17. I only get the product logo. Illustrator and Photoshop thumbnails are fine (updated 11/2 and 11/14, respectively).

ALSO DRIVING ME NUTS.

same here. and i'm working with files in my desktop - no pen drives or similar.

Hello. Will there be a reply to all those comments? I have the same issue even just saving to my hard disk.

I'm getting the same issue Illustrator CC 2018 22.0.1 Mac OS 10.13.1

Getting the same issue during Save. High Sierra 10.13.1 + Illustrator 22.0.1. No external drives.. Just saving on computer hard drive. Error seems very intermittent, but keeps popping up.

Seems to be after upgrading to High Sierra and doing the latest Adobe update on 11/17/17. I am saving to my external Seagate drive right next to me. The other problem is that I no longer have thumbnail images for Illustrator ai or eps or Photoshop psd files. I only get the product logo. Please give us some solution. It's driving me nuts.

Also applies to files being sync'd with a Box.com account

I updated Illustrator (22.0.1) and my OS to 10.13.1 about the same time, and the issue occurs while working on files located on a local Thunderbolt RAID array.

I'm getting the same issue with Illustrator CS2018 on 10.13.1. I'm saving opened/worked on files onto an exterior drive which is formatted as Mac OS extended (journaled). It's doesn't always happen every time I save and I haven't been able to replicate what triggers it. I doesn't appear to cause a problem with my files other then being annoying extra step.

It started for me after installing High Sierra. A file worked on and saved several times before the installation - with no problems. I just tried a "save as" for same file with same name, and have changed it 3 times since then without repeat of the problem. No guarantees but worked for me.

I have seen this message even when saving files to my desktop. The files seems to start out okay and I don't see this message until I have saved the file many times.

I have NOT been saving to Dropbox and still, I get this message. For the most part I save either to an external USB SSD or to my desktop while working on files. My desktop is synced to iCloud however. I am running latest version of Illustrator.

So I got this "problem" when I want to save my illustrator file. Sometimes when I click save, it tells me that this file was edited outside of illustrator and asks if I want to continue. I can click Yes and everything is fine, but getting that message is kind of annoying and doesn't make any sence, since that file is only on my desktop and nobody else can even take a look at it or edit it from somewhere. Sometimes I just change a color and that message appears when I want to save that file, sometimes there is no message...
I have Illustrator CC by the way (a german version if that matters).

Not just DropBox but it definitely seems to be related to saving to a "non-local" folder. I see it when I am saving to either a DropBox folder and also a GoogleDrive folder.

Holy cow, I just upgraded to High Sierra and immediately discovered the same problem as everyone else with Illustrator (CC 21.1.0) and Dropbox(v39.4.49). I save to a folder on my hard drive, which is synced to Dropbox. After that file has been synced to Dropbox, something mysterious happens and Illustrator thinks the file has been altered (name change, or something?) outside of the application. So, when trying to save that file again from within the application, the message pops up. Only happens with Illustrator, and started happening immediately after upgrading to High Sierra (10.13.1) Been working in this same manner for a couple years with no issues until now.

I don't use dropbox but sometimes i get same message since i have updated High Sierra (not while working on ALL of my illustrator files - i don't know what causes this problem).

Running Illustrator CC 2017.

Hi, I don't use dropbox but I do use iCloud and also I use an external server (lord knows where it is) as I work at home. The problem occurs when I use the the drawing tools and then try to save to my desktop which is connected to iCloud. It doesn't happen when I update a drawing using the data plotting devices. I am running OS 10.13.1 on an 2015 iMac and also a 2016 MacBook Pro also running OS 10.13.1. Running Adobe Illustrator 2018 version. Thanks

Same problem, happens with high sierra and illustrator 2018. Happens only with Illustrator.

Same Here! Really Anoying.