iPhoto Program not compatible with update 11.4 Help

This is really simple - and answered here hundreds upon hundreds of times:

iPhoto was discontinued 6 years ago. It is no longer developed or sold. It was replaced by the more powerful (and free) Photos.app that comes with the OS. You can migrate to that app very simply:

Hold down the option (or alt) key and launch Photos. From the resulting menu select 'Choose Library' and point at your iPhoto Library. It will do the rest.

If you prefer not to use Photos there are several 3rd party apps that you can use. Which to choose depends on the kind of photographer you are and your budget.

Sorry, this is not quite clear: "This updated version is not compatible with iphoto 10.13 Sierra" ?

Did you just upgrade from macOS 10.13 High Sierra to Big Sur? Have you been using iPhoto on the older system or Photos? I am asking, because there are two possible reasons for not being able to access the photo library.

• As Yer_Man explained, iPhoto is no longer compatible with any system versions newer than macOS 10.14 Mojave and we have to switch to a different application, for example Photos.
• But occasionally we have seen reports, that users could no longer launch Photos as well after a system upgrade. This can happen, if you are keeping an alias to Photos on your Desktop or the icon in the Dock is still linked to an older version of Photos. if you cannot launch Photos by clicking the alias on the Desktop or the Dock icon, open the Applications folder and find the current version of Photos there. Double click the Photos.app in Applications to launch Photos. This will ensure that you are launching the current version installed by the system upgrade and not an older left-over from the previous system version.