CIS Auto-Sandbox Causing Adobe Reader XI Problem


Just downloaded the latest free CIS which installed okay. However I now have an issue with Adobe Reader XI. The first time that I open any .pdf file that was created before CIS was installed, the file is sandboxed, Adobe Reader opens the file and slows down, goes blank then the image of the file returns. It does this several times before the following Adobe error message window pops up. “There was an error during initialization. An internal error occurred”. When opening the .pdf file, if I click on the CIS “Don’t sandbox again” then eventually close the .pdf file, the next time that I click on that file, it opens and works without a problem. If I disable CIS Auto-Sandbox, all my .pdf files open okay the first time. Does anyone have the answer?

I have a brand new HP Desktop, OS: Win 8.1, nothing much downloaded and installed yet. CIS full scan showed nothing untoward. I’m not an Internet Security geek so please keep that in mind if/when you respond.

Thanks in advance.

I have also been having this problem for a while now. When I try to open Adobe Reader XI files from my flash drive, it isolates the file. Even if I tell it to ignore the file, the act of virtualizing it causes Adobe to lock up. If I do get it to load properly, I will be unable to save any changes I make to the file because it’s open in a virtual environment, so I have to reload every file that I need to work on.

I could not see a way to make Adobe an exemption in the sandbox list - I tried to make the folder on my flash drive exempt, but that didn’t do anything. So I turned off the sandbox, and now I’m getting a warning from Windows that my malware protection has been turned off. There MUST be some kind of solution here - this is really affecting my productivity!!

HP Pavillion Notebook
Windows 8.1 64-bit
Adobe XI 11.0.10


I’ve discovered that the problem only appears to occur when trying to open .pdf files located on an external storage source, in my case 02 flash drives [memory sticks]. .pdf files open okay if located on my Desktop.

When attempting to open a .pdf from an external source. CIS cuts in with the following window:

“Comodo Sandbox - Application Isolated - .pdf file has been Run Virtually”

If I click on: “Don’t isolate it again” the problem with Adobe XI commences but eventually Adobe Reader will close. The next and subsequent times that I open the .pdf file, CIS doesn’t intervene and Adobe XI Reader opens the file correctly. If I don’t click on: “Don’t isolate it again”, until I go to the CIS “Unrecognised Files” window and move the .pdf file to “Trusted Files” the problem with Adobe XI Reader persists each time that I attempt to open that .pdf file.

I raised this issue with Comodo - Ticket: CIT-416-43425 on the 07th March 2015 and received a response requesting further information which I supplied. Since then Comodo has been silent on this matter.

Will you please fix this bug and issue an update.

I would love to see a fix - have upgraded to Acrobat DC, but COMODO continues to isolate the pdf files when opening. Thanks for the tip about the external/flash drive. I guess I will have to copy the files over before working with them. :-\

Hi mrsb33

The only communication that I’ve had from Comodo is to inform me that they are working on a fix.

However, after installing the latest CIS Product Version, all of my .pdf files now open first time from any location. CIS appear to have fixed the bug.

To check which Product Version that you have currently installed on your computer, do the following:
Open CIS Home window
Click on “?” [top right hand side] and a small menu will unfold
Click on “About
Check “Product Version

The latest CIS Product Version is:

CIS usually automatically checks and updates the CIS programme files [Product Version] when it automatically checks and updates your Antivirus Signature files.

If it hasn’t, you may want to check your CIS “Update” settings.