I found this in the config for 14.26:

SNIP...................................
troublershooting {
B:disableCustomVertexFormats=false
B:enableFaceLightmapExtraction=true
B:useGetLightValue=true
}

troubleshooting {
B:enableAPITestingItem=false
B:logTileErrors=false

Was that a typo or do those two sections do different things?

Thanks!

For any bug reports please provide the following details as well,

• MC Version:
• C&B Version:
• Do You have Optifine:

Yeah, looks like a typo put those options in two different categories instead of 1, thanks will be fixed in future releases.