In some cases some vehicles from Official pack have transparent textures or overshading problems.

Fixed in V20.0.0.

Odd, is it only OCP vehicles that have this issue?

Yes. This problem has appeared before this issue has appeared. First, I turned on the shaders and saw this Scout's textures' bug. Later I have lost any ability to turn on the shaders in any world having any IV vehicles. I think these problems are interrelated. I think it's worth checking out. I can also offer you .log files of that day. It might also help the bugs' investigation.

The shaders crash you referenced is due to a fix I implemented to prevent odd sound corruption and flashing vehicles referenced in #169. If the OCP vehicles had this issue before that, it must be due to something in my rendering routine that only affects OCP vehicles. Likely something due to transparency or something. Will have to investigate. Can you tell me what shaders/version cause this so I can reproduce it on my end?

Any shaders cause the case. You can use the YouTubers' Dream Shaders download link.

@DonBruce64, New info about this issue! OCP Vulcanair has texture transparency while taxiing with shaders turned on.

Again "Can you tell me what shaders/version cause this so I can reproduce it on my end?" Showing me a picture of a bug won't help if I don't know your exact configuration.

@DonBruce64, Again: "Any shaders cause the case. You can use the YouTubers' Dream Shaders or the TME Shaders."

Whoops. Sorry about that. Didn't see that....

So I made a bunch of changes to the rendering as of late. @StarterCraft, you able to test on V18.4.0?

Same comment about V19.0.0. I've completely re-done the rendering system in that version, so I don't see any reason why vehicles would be holographic in that version.

So in V18.0.0, I made numerous changes to make the lights better. Next cycle will address other shaders issues with rendering the main vehicle model.

Realized I might have to ping you @StarterCraft

Hi @DonBruce64! Sadly, I had no time to update my instance of IV this month, so I have not tested the update.

@StarterCraft No worries. Whenever you get a chance let me know. Trying to wrap up all my tickets before I try to put to newer MC versions.