I was trying to connect to my dev org using my force.com IDE and i got an exception
"com.salesforce.ide.api.metadata.types.Metadata$JaxbAccessorF_fullName cannot be cast to com.sun.xml.internal.bind.v2.runtime.reflect.Accessor"
Any idea on what could be the reason for this?
I found a workaround
Switching the workspace back to the same workspace you had problem with solved it.
File -> Switch workspace -> [Select the same workspace you had problem with]
Not sure why it worked.. But it WORKED 🙂