"This IDoc data record cannot be edited - field is too long" - Issue

Hey All,

When I try to edit the E1BPEXTC segment of Idoc type ACC_GL_POSTING01 in WE02, it throws me an error saying "This IDoc data record cannot be edited - field is too long". Has anyone come across this Issue before. I am on ECC 6.0.

Any suggestion is highly appreciated.

Thanks.