You are trying to edit a resource file that is a part of another project item (such as a form or a control). Editing this ...

You are trying to edit a resource file that is a part of another project item (such as a form or a control).  Editing this item could corrupt the project item, and you will have to recover it by hand.  In addition, changes made to this resource file may be lost if further changes are made to the project item.

Do you really want to edit this file?