There is an issue with a Microsoft security patch and .Net 4.7.1 on Windows 7 or Windows 2008.
It does not appear to affect Windows 10 or Server 2012 and later.
Microsoft is releasing new information on this issue daily.
It is not natively a 4.7.1 issue, but rather a security update that accompanies it. (KB4055002 or KB4055532)
Removing the patch and/or .Net 4.7.1 will resolve the issue.
You will need a version of .Net for the application to run. You can install .Net 4.5.2 to satisfy the requirement.
If you still need 4.7.1, you can follow this. (It will be secure according to these steps)
More information can be found here.