Xcode 12.4 Swift Files Missing

Hi

I'm using Flutter to do an IOS app using Xcode. I'm currently using version 12.4 on my MacBook Pro mid 2012.

When I try to run it on the IOS App simulator, I'm getting a long error message. here is a snippet of it

Xcode's output:

↳

    ld: warning: Could not find or use auto-linked library 'swiftSwiftOnoneSupport'

    ld: warning: Could not find or use auto-linked library 'swiftObjectiveC'

    ld: warning: Could not find or use auto-linked library 'swiftCoreFoundation'

    ld: warning: Could not find or use auto-linked library 'swiftCompatibility50'

    ld: warning: Could not find or use auto-linked library 'swiftDarwin'

    ld: warning: Could not find or use auto-linked library 'swiftUIKit'

    ld: warning: Could not find or use auto-linked library 'swiftQuartzCore'

    ld: warning: Could not find or use auto-linked library 'swiftCore'

    ld: warning: Could not find or use auto-linked library 'swiftCoreGraphics'

    ld: warning: Could not find or use auto-linked library 'swiftCompatibility51'

    ld: warning: Could not find or use auto-linked library 'swiftFoundation'

    ld: warning: Could not find or use auto-linked library 'swiftCoreImage'

    ld: warning: Could not find or use auto-linked library 'swiftCompatibilityDynamicReplacements'

    ld: warning: Could not find or use auto-linked library 'swiftMetal'

    ld: warning: Could not find or use auto-linked library 'swiftDispatch'

    ld: warning: Could not find or use auto-linked library 'swiftCoreMedia'

    ld: warning: Could not find or use auto-linked library 'swiftCoreAudio'

    Undefined symbols for architecture x86_64:

Try doing research and think it might be linked to framework issue but not sure. Can anyone possibly advise?

Thanks

Eddie