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# Unable to open ConfigSource file

![](https://4182918922-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MLIxsxy-PG49XtZX5uS%2Fuploads%2FDeABSCAvNzlobu55TiRa%2Fconfigissue.PNG?alt=media\&token=5c06acd1-433a-4791-937b-47ea2661f3a1)

This is due to the Build Action being changed on the file - 

![](https://4182918922-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MLIxsxy-PG49XtZX5uS%2Fuploads%2FmFTN7rAVl3QL9O4MCNO4%2FnoneContent.jpg?alt=media\&token=f89679b4-d853-4b9e-8deb-fcdbb16a8835)

To fix, just check all the files that have had the Build Action changed and change back to Content.