Why do I get the error message "faircom.rtg.CtreeEnv.ct_config2(IJJ[Ljava/lang/String;)J" when using c-treeRTG?

This error indicates that the ctreej file handler is being used to connect to a c-treeRTG version 10 or earlier which requires the "ctree2" file handler instead.
You can reproduce it using the simple command:

   iscrun -J-Discobol.file.index=ctreej com.iscobol.rts.Version

and get the same error. It works properly when the "ctree2" file handler is used instead:

   iscrun -J-Discobol.file.index=ctree2 com.iscobol.rts.Version

Here's a list of the correct value of iscobol.file.index for each c-tree version.

• c-tree version 9.5.51961 or previous: Use "ctree"
• c-tree version 9.5.53702 through 10.4.0.39110: use "ctree2"
• c-tree version 10.4.0.39701 or later: use either "ctreej" or "ctree2".

You can read more about this in Veryant's documentation, c-treeRTG for COBOL book, section "Accessing from isCOBOL".