vb.net application stopped working on 64bit machines

hillcook used Ask the Experts™
I have a vb.net Windows Forms application compiled in Visual Studio 2013 using .NET 4.0 (not client profile), x86 target cpu.  The application has been running on multiple machines across dozens of networks for several years.  Suddenly a couple of weeks ago it stopped running on 64 bit machines on 1 network. 32 bit machines still run it from the same server. 64 bit machines are running .NET 4.6. Windows updates were rolled back, firewalls turned off, running as administrator, anti virus turned off, user network permissions are good. Any tips would be greatly appreciated.
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John TsioumprisSoftware & Systems Engineer

At first i think the best thing is to share the error if any...unless you mean that the application just dies with no sign.
Then you should try to run it as an Administrator...maybe something in the permission is blocking
Last is to install Visual Studio and one of these x64 machines and open the solution and see where and why its failing...
Scott McDaniel (EE MVE )Infotrakker Software
Most Valuable Expert 2012
Top Expert 2014

Also check the Event Logs on the machine where it fails.

Have you tried compiling it with AnyCPU instead of x86?
I'm able to recreate issues by removing all .NET versions except 3.5.1 and 4.6.2.  Looks like linq takes issues with that.  installing the 4.6.2 SDK seems to take care of it.  Thanks for the assistance.


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