I upgraded from macOS Catalina (10.15.7) to Big Sur (11.5.1) going from an Intel i7 MacBook Pro to an M1 iMac subsequently upgrading to Xcode 12.5.1 from 12.4
The iOS app will compile and run on a device -- as well as a simulator. However if I try to Archive I get the titular error of this post. The error sort of references an Info.plist or the Watch app but is it cryptic and not that specific. I suspect it's something to do with my companion watch app.
ValidateEmbeddedBinary /Users/$USER/Library/Developer/Xcode/DerivedData/$PROJ-hkuuspnqxnzkxfdjlwwluxskiqbs/Build/Intermediates.noindex/ArchiveIntermediates/Watch/BuildProductsPath/Release-iphoneos/$PROJ.app/Watch/Watch.app (in target '$PROJ' from project '$PROJ')
cd /Users/$USER/Documents/$PROJ/$PROJ/Applications/Xcode.app/Contents/Developer/usr/bin/embeddedBinaryValidationUtility /Users/$USER/Library/Developer/Xcode/DerivedData/$PROJ-hkuuspnqxnzkxfdjlwwluxskiqbs/Build/Intermediates.noindex/ArchiveIntermediates/$PROJ/BuildProductsPath/Release-iphoneos/$PROJ.app/Watch/Watch.app -signing-cert 0B2269280E4CC1330AD714C0EC8A51DF24A35DB9 -info-plist-path /Users/$USER/Library/Developer/Xcode/DerivedData/$PROJ-hkuuspnqxnzkxfdjlwwluxskiqbs/Build/Intermediates.noindex/ArchiveIntermediates/$PROJ/InstallationBuildProductsLocation/Applications/$PROJ.app/Info.plist
I have managed to get it to Archive twice -- seemingly after making big changes at the project level. Once I embedded a framework and it archived -- then I added an entitlements file and added a line to point to it in the xcproject.pbxproj file. Producing a minimal working example of this will be tricky as I suspect it's a race condition in bigger projects.