If you are using Revit 2018 version in addition with Archvision Plugin (Entourage*) and V-ray you Revit session could crash, this is duo a compatibility issues between ArchVision Entourage* Add-on Plugin and the V-Ray for Revit Plugin on Revit 2018 Version.
*The only function of the ArchVision plugin is to create and apply Entourage Workshop styles to your RPCs.
As a workaround, you can avoid opening the ArchVision to evade crashing revit or if you not planning to use the V-ray Plugin you can temporarily stop the V-Ray from loading by moving the V-Ray *.addin file (located in C:\ProgramData\Autodesk\Revit\Addins\2018) to a new temporary location and restarting Revit. (you can use the V-ray plugging again by moving the file back to the original location.)
We are working diligently with Chaos Group to resolve the issue as soon as possible.