V-Ray is a popular rendering engine used in conjunction with various 3D modeling software, including SketchUp. The version you're mentioning, V-Ray 3.6 for SketchUp 2018, suggests you're using an older version of both SketchUp and V-Ray.
Before installing, close SketchUp 2018 completely. Vray 3.6 Sketchup 2018 Patch
The journey began on a typical Tuesday morning, as Alex poured over online forums and blogs, scouring for any mention of the patch. Hours turned into days, and days turned into weeks, but Alex refused to give up. The architect's searches led to a maze of dead ends and broken links, but still, they persisted. V-Ray is a popular rendering engine used in
Remember: If a “patch” feels too good to be true, it is. And in the case of V-Ray, it’s also a felony. Crash on Startup : If SketchUp or V-Ray
Chaos allows users with a valid account to download older versions (back to V-Ray 3.6) if they have an active subscription. Instead of a patch, buy one month of V-Ray ($60–$90) and then download the legacy 3.6 installer for SketchUp 2018 from the official Chaos download portal.
Full support for SketchUp 2018 in V-Ray 3.6 for ... - The Chaos Blog
: This is the standout feature, allowing users to leverage both CPU and GPU simultaneously. For those with NVIDIA CUDA hardware, this maximize system resources and significantly reduces wait times.