This was driving me nuts and there have been a few other Forum posts and articles that talked about various antivirus errors with this number.

Essentially Kapersky (and I assume other antivirus products) are blocking certain actions with Laserfiche when it comes to electronic documents, which are downloaded to a temp file on your machine and opened from there. What was really mysterious with Kapersky is that the first time you downloaded a particular document it worked - but the second (and subsequent) times it failed. 

For Kapersky version 8 I have included a screenshot showing the changes I made. 

You need to go into your settings for Kapersky, endpoint control, web control and add a new rule. 

We set the new rule to allow the following:

Filter Content:  Any content

Apply to Addresses:  To individual addresses

Action:   Allow

Rule Schedule: Always

we then added the IP address of the LF server in. 

Once we Ok'd that rule and saved we were able to open up all of the electronic documents without any issues.