Why does my .NET application crash when run from a network drive?

Question

My .NET application fails when run from a network drive even when the very same executable runs perfectly fine from a local hard drive?

I tried checking for "Full trust" like so:

try
{
    // Demand full trust permissions
    PermissionSet fullTrust = new PermissionSet( PermissionState.Unrestricted );
    fullTrust.Demand();

    // Perform normal application logic

}
catch( SecurityException )
{
    // Report that permissions were not full trust
    MessageBox.Show( "This application requires full-trust security permissions to execute." );
}

However, this isn't helping, by which I mean the application starts up and the catch block is never entered. However, a debug build shows that the exception thrown is a SecurityException caused by an InheritanceDemand. Any ideas?

Answer 1

It indeed has to do with the fact the apps on a network location are less trusted then on your local hdd (due to the default policy of the .NET framework).

If I'm not mistaken Microsoft finally corrected this annoyance in .NET 3.5 SP1 (after a lot of developers complaining).

I google'd it: .NET Framework 3.5 SP1 Allows managed code to be launched from a network share!

Answer 2

Did you try Using CasPol to Fully Trust a Share?

Answer 3

You may have already done this, but you can use CasPol.exe to enable FullTrust for a specified network share.

For example

cd c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727
CasPol.exe -m -ag 1.2 -url file:///N:/your/network/path/* FullTrust

More info here.

Answer 4

If this is .NET 2.0 or greater, ClickOnce was created to really help with this deployment stuff. I only deploy to network shares using that.

Answer 5

This is security built in by microsoft into the .net framework. It's a way of stopping malware to be run locally with full priviliges, so you cannot change this programmatically in the code.

What you need to do is increase the trust of specific assemblies. You do this in the .NET Framework Configuration (Control Panel->Administrative Tools), and has to be done on each computer.

As with any security measures, it's a pain-in-the-ass, but will help the world to be less infected etc...

Answer 6

All I had to do was mark the files Read Only (possibly unrelated) and give all permissions except Full Control to Authenticated Users. I was encountering this issue before I did that, when I had the network share only setup for Domain Users.

I discovered this workaround because neither the admin shares (\server\C$) nor my own PC's shares had this problem.

Edit: App is targeting .NET 3.5, no SP1 here (version 3.5.7283)