About This File
I am unsure of the author of this document but it describes how to recover an Allen-Bradley FactoryTalk (used to be RSViewStudioME) project from uploading the MER file from an Allen-Bradley PanelViewPlus HMI.
FactoryTalkStudio downloads a compiled file (.MER) into a PanelViewPlus but one will have the dickens of trouble trying to upload and open a MER file. The full FactoryTalkStudio application is an APA file.
So if you do not have access to the full APA project file such as an OEM builder did not provide it to you then upload the MER file from the PanelViewPlus and give this procedure a try.