Help! How do I fix an "illegal or misplaced operator" error in Adobe Illustrator?

[NaplesEagle8950]

I'm working in a very large file in Adobe Illustrator, around 3GB in size.  I've been able to save successfully, close and reopen - UNTIL - I moved the file over to an external drive.  Upon doing so, whenever I try to re-open the file I get the following error:

Adobe Illustrator Error Message:

I'm able to see a preview of all of my art boards with the associated work when I go to File/Open..and click on the file in question:

Adobe Illustrator thumbnail preview of my corrupted file:

However, when I click open, most of the art boards are blank.

I've searched up and down the Adobe forums and other places on the internet for a solution.  I tried three suggestions, all with no success: 

1.  I've tried the trick where you save the document as an .EPS and try to insert it into a new Illustrator document. 

2.  I've tried "placing" each page into a new document inside of Illustrator, Photoshop and InDesign. 

3.  I've tried changing my Illustrator preferences  /enableContentRecovery from 0 to 1.

     I downloaded a text editor that's able to read very large files.  I tried searching for the error inside of the code, but was unable to find that string of text from the
      error message, I searched for "1_iu" the last characters in the error message.

Details:

Computer: 64 bit, PC.

AI Version: CS6

System: Windows 8.1 Pro.

Problem: .AI file saved successfully, and I was able to reopen it on my desktop.  I had to move the file over to a different drive, and when I tried to open again received the illegal or misplaced operator error.

None of the solutions I'm finding have fixed my problem.  I'd like to understand why the error occurred so I don't repeat the mistake, and I'd like to find out a solution to recover my file.  I don't understand how if Illustrator can show me a preview of all of the pages...why the actual document comes in as blank pages?  Please help!

[Monika Gause]

Can you just transfer the file back to your hard disk and open it from there?

[NaplesEagle8950]

I tried that I'm receiving the error message from the copy on my hard disk, as well as the file saved to the external hard drive.

[Monika Gause]

The problem is working on an external hard drive. Illustrator might have errors with that workflow.

Illustrator support for networks and removable media

Troubleshoot issues with networks, removable media in Photoshop

You might try the following:

Services:

http://www.recoverytoolbox.com/buy_illustrator.html

http://markzware.com/adobe-software/fix-illustrator-file-unknown-error-occurred-pdf2dtp-fi le-recove...

http://www.illustrator.fixtoolbox.com/

DIY:

http://daxxter.wordpress.com/2009/04/16/how-to-recover-a-corrupted-illustrator-ai-file/

http://helpx.adobe.com/illustrator/kb/troubleshoot-damaged-illustrator-files.html

http://kb2.adobe.com/cps/500/cpsid_50032.html

http://kb2.adobe.com/cps/500/cpsid_50031.html

http://helpx.adobe.com/illustrator/kb/enable-content-recovery-mode-illustrator.html

[NaplesEagle8950]

I was able to find the line of text from the error message just now in my text editor, deleted it, saved a copy and reopened.  A new error message comes up now saying the following: