Ask the Experts / Coaster Trains Showing Up as Random Sprites?

I don't know if this is the right place to put this, but I've been having this problem with OpenRCT2 for a long time. Sometimes, certain types of coaster trains won't load and will just show up as random sprites. I used to only have this problem with custom trains, but it's started to spread to the ones in-game, too, and what trains are affected differs each time I load up the game. Here's an example:

 

 Paramounts Electric Fields 2019-06-27 23-06-52.png (1.43MB)
downloads: 32

 

Does anyone know what's causing this? More importantly, how do I fix it?

Not sure what the cause is, but just restarting the game has worked for me.  This only seems to happen after long periods of play/leaving the game open though. 

Yeah, it's an issue when you load up a sv6 while already in another park. As opposed to loading a sv6 from the main menu.

Just quit to the main menu everytime you want to open a park and you should be fine. Not really much to worry though, the glitched trains aren't permanent even if you save with then.