A problem with Trueview not displaying dxfs occurred after installing free Blue-beam. I tried reinstalling Trueview after uninstalling Blue-beam. I tried reinstalling the Intel drivers that match the Dell computer. Final solution was that a second printer driver from NVIDIA somehow installed with Blue-beam or came to life after installing Bluebeam. don't have a clue where it came from in that I have never owned a Nvidia graphic card. Deleted the Nvidia driver and Trueview once again displays DXFs and acts normally again.
A second issue was that nothing printed after installing Blue-beam. Blue-beam PDF was my only remaining print driver and it fought everything. All of my printer drivers were corrupted and needed to be reinstalled after uninstalling Blue-beam.
I have Blue-beam on several other computers and this Dell is the only one with major problems. However, Bluebeam pdf is rather insidious, we have stopped using it.