When I skip my recording forwards or backwards using the time line at the top of the screen the world usually renders normally.
But, I have found that skipping backwards to 2 seconds or lower causes the world to not render although I can still see the sky. The rendering can be rectified/fixed by playing the recording for a second.
https://youtu.be/W8nnptsVOkw
Windows 10 64bit
Intel i7 2700
8 Gb RAM
Forge 1.12.2-14.23.4.2707
Replaymod 1.12.2-2.1.3
Java etc all at the latest version
NOT using Optifine
EDIT: Just tested with Optifine 1.12.2_C9 but issue persists