Shadow Error with Real Train Mod (added Details)

[Omori1106]

MC version: 1.7.10
Sign Picture Mod version : 2.8.0 universal
Forge : 10.13.4.1558
Other Mod : Real Train Mod(1.7.10.35), NGTLIB(1.7.10.27)
No crash report has been occured.

When place minecraft sign, using this mod with Real Train Mod & NGTLib, Shade error is occured.
All Real Train Mod blocks and rails which were placed near sign, lost their shade.