Bug || Weird Bright Blue Lines

Hello everyone! I am currently designing a low poly obby, and I encountered an interesting bug. There is a near-transparent overlay above the water, to make it more realistic. I am using Shadow Map lighting and I have the Realism Mod’s lighting equipped too. When I added terrain and props, the shadows looked normal, but with the bright blue outline. I want to get rid of this outline as it doesn’t look very good. All the meshes affected by the lighting has a shadow with a bright blue outline. How can I fix this?