Updated: 7/21/2021 12:17 PM CST
According to the GeForce Now Status page, it appears that Conan Exiles appears to be fixed and that they are monitoring the issue to see if everything is good to go.
For those who have the latest DLC, Isle of Siptah, you should not be experiencing any issues. However, if you do not have the DLC, and you try to launch the game on GeForce Now, you will be met with an error at launch.
NVIDIA is currently aware of the issue, and they are investigating the cause.
Conan Exiles DLC issue: Investigating - Conan Exiles is available to play for users that own the DLC Isle of Siptah. Uses that do not own the DLC will get an error at launch. We are currently investigating this issue and working on a fix.
Jun 29, 10:59 PDT
We will update this post with any updates once they are available from NVIDIA.