Problem with NameMapping / importation is mandatory

You can add your name mapping file from proj1 as an existing file to proj2. We have done this in the past to share a name mapping file across multiple projects.

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  Right click on the project tree node, add existing file. Select the proj1 name mapping file using the file browser.

If it is just a one time sync you need to do, you can merge the two name mapping files.

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  Right click on the name  mapping file in proj 2, right click and select merge.