I was getting the error when I tried to create a new component... I uninstalled it, deleted all the jdeveloper/version directories under users/<user>... tmp and it seems to be working now. It must have been some migrated preferences....
well it didn't go away. I get the error "exit dialog" now if I am building a database diagram I get
Performing action Copy[ from oracle.modeler.addin.ModelerEditor ]
java.lang.IllegalArgumentException: Invalid double value
It doesn't tell me where and I cannot save..... jdev 184.108.40.206 seems to be pretty buggy. I did not have these issues in 220.127.116.11