Windows 10 x64
Java 8 Update 73 (64 Bit)
Forge version 11.14.3.1521 (the only version of forge I could find that doesn't crash on multiplayer servers)
Shaders mod installed (but not in use while in replay mode)
The bug I found is that, while spectating an entity, the water render really strangely. Here is a screenshot.
As you can see, the water textures render in front of everything. This happens in every replay I have been in so far. This does not happen while flying around normally as you can see here,
