Why do I get 'ct_init ERROR 19:530:0' trying to work with the c-tree Server?

The 'ct_init ERROR 19:530:0' means that the client c-tree does not match the server c-tree.

In your environment, the c-tree client loaded by the isCOBOL framework depends on the first c-tree client library (ctree.dll on Windows, libctree.so on Linux/Unix) available in the library path.