vb.net application stopped working on 64bit machines

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.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

John TsioumprisSoftware & Systems EngineerCommented:
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 (Microsoft Access MVP - EE MVE )Infotrakker SoftwareCommented:
Also check the Event Logs on the machine where it fails.

Have you tried compiling it with AnyCPU instead of x86?
hillcookAuthor Commented:
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.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
hillcookAuthor Commented:
.net version
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Visual Basic.NET

From novice to tech pro — start learning today.