No engine plume and vehicle phasing through terrain

[AlmightyM3]

Game Version​

2026.4.18.4206

Operating System​

Windows 11 Pro

System Info​

Processor: AMD Ryzen 7 5800X
RAM: 32 GB
GPU: NVIDIA GeForce RTX 3060 Ti, 8 GB VRAM

What Happened​

None of the engines on the default spacecraft in testing mode have visible engine plumes, although they still have the startup effects, sound effects, and heating effects. The rocket also seems to go through bumps in the terrain but not flat terrain.

What Was Expected​

Visible engine plumes and interactions with terrain features is expected as that is what occurred in previous versions, such as 2026.2.5.3428.

Reproduction Steps​

1. Start KSA in testing mode. (I have not tried other modes so I do not know if it also occurs there.)
2. Try starting any engine on the default craft, no plumes will be visible.
3. Upon deorbiting, the rocket does not interact with hills and bumps in the terrain.

Reproduction Rate​

Always.

Additional Info​

See attached photo for an example, I also have a video but seem to be unable to upload it.

 

[SToRME]

Same issue here.

CPU: AMD Ryzen 7 5700X
RAM: 32 GB
GPU: NVIDIA GeForce GTX 1070 Ti, 8 GB VRAM