When using a 12.3 Automic.dll file (of version 12.3.8 or earlier) to run the dot.net based Application Interface to connect to a 21.0 the CP throws the following error:
java.io.IOException: Different versions on server (21.0) and client (12.3.).
at com.uc4.communication.Connection.<init>(Connection.java:312)
at com.uc4.communication.Connection.loadBalancing(Connection.java:638)
at com.uc4.communication.Connection.open(Connection.java:515)
at com.uc4.communication.Connection.open(Connection.java:445)
at com.uc4.communication.Connection.open(Connection.java:422)
at CreateJob1232_to_2104.CreateJob1232_to_2104(CreateJob1232_to_2104.java:61)
at CreateJob1232_to_2104.main(CreateJob1232_to_2104.java:51)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:272)
Release : <= 12.3.8
Only 12.3.9 HF2 Application Interface can connect to 21.0.4 (and higher). Recompile any java programs to use the 12.3.9 HF2 uc4.jar file.