unable to add local attributes ,String ,Integer

Hi All,

Can you help me unable to create local attribute and i did excuted belows commands for windchill shell  but  columns are not creating 

the commands

AddColumns wt.part.WTPart  -f String=2

AddColumns wt.part.WTPart String=1

Following error i got 

C:\ptc\Windchill_12.0\Windchill>windchill start

C:\ptc\Windchill_12.0\Windchill>AddColumns wt.part.WTPart String=1
Validated type wt.part.WTPart
Schema validation successful. Updates will attempt to proceed.
Generating class & introspection files for type: wt.part.WTPart
error: cannot access module-info
bad class file: C:\ptc\Windchill_12.0\Windchill\codebase\module-info.class
class file has wrong version 61.0, should be 55.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
1 error
ERROR : com.ptc.core.lwc.server.addColumns.ClassfileGenerator - Failed to compile the generated annotated source files for type: wt.part.WTPart
wt.util.WTException: Failed to compile the generated annotated source files for type: wt.part.WTPart
at com.ptc.core.lwc.server.addColumns.ClassfileGenerator.generateNewSrcAndClassfile(ClassfileGenerator.java:185)
at com.ptc.core.lwc.server.addColumns.AddColumnsImpl.performAction(AddColumnsImpl.java:227)
at com.ptc.core.lwc.server.AddColumns.addColumns(AddColumns.java:70)
at com.ptc.core.lwc.server.AddColumns.main(AddColumns.java:46)
AddColumns failure. Review the console error message and upgrade_tool.log in the current directory for more information.

C:\ptc\Windchill_12.0\Windchill>
C:\ptc\Windchill_12.0\Windchill>

Thanks & Regards

Sarathkumar M