OK, so you want to go into your Control Panel and look to see what version of .NET is installed. On this machine it is 4.6.1
You may need to update this as its something that can be easily overlooked.
As for how to open the .dmp files if you are using Microsoft Visual Studio you right click on the .dmp file and click on OPEN
You should get this pop-up and you mark "Select a program..." and click OK. A new window pops up and you locate your Microsoft Visual Studio and choose it.
Once you have selected MS Visual Studio it should open and looks like this. For this .dmp it appears there was a permissions issue based off what is in the "Exception Information".
If you don't have MS Visual Studio you could go get one of these free tools to dig into the .dmp 3 Ways to Analyze Memory Dump (.dmp) File • Raymond.CC