When B:EnableShaders=true is set you will get the following graphical artifacts for better portals:

Screenshots were taken on Minecraft version 1.12.2 with

• Forge 1.12.2-14.23.5.2838
• p455w0rdslib-1.12.2-2.2.156.jar (md5sum 56a57b60eff38f98cf0228b802df2322)
• betterportals-0.3.7.1.jar (md5sum d11bf3d057509a11b8738df604094d46)

The issue does not appear when EnableShaders is set to false.

Related issue in the Better Portals repository: Johni0702/BetterPortals#410

I'll be removing the shaders stuff from pwlib. Thanks for the report :)

should be resolved since I removed shaders