My iPhoto events have gone when moving to Photos, yes checked albums and sidebar, iPhoto events ,and,it's,a,mush,mash,of,5000 ,photos.,Checked,sidebar,,Photo,events,,same,issue.,Why,has,this,happened,,crap.

Photos is a very different application from iPhoto. There are no longer events. The library is automatically structured by Photos and the set of photos split into Moments, years, collections, based onto the date and the location, if available.

All your albums will have been migrated to Photos, if Photos can simulate them. Not all smart albums can be recreated in Photos, if they are based on smart rules, that are not available in Photos.

Your events should be visible in the folder iPhoto events in the album section -as additional albums. If they are not there,, you either migrated a different iPhoto Library, or iPhoto Library has been corrupted and could not be migrated properly because of that.

If your events are really not in the iPhoto Events folder in the Album section, repeat the migration:

Try to repair the Photo Library with iPhoto before trying to upgrade it.

Make backup of your iPhoto Library and run the iPhoto Library First Aid tools to repair the permissions on your library and rebuild the iPhoto Library.

• To launch the First Aid Tools hold down the alt/option and the command key simultaneously while double clicking the iPhoto Library to launch the iPhoto Library First aid tools. Hold down both keys firmly and long enough, until the First Aid panel will appear.
• Try both the options "Repair Permissions" and "Rebuild library".
• Then delete the failed Photos Libraries from the Pictures folder. Empty the Trash.
• And try again to migrate the iPhoto Library to Photos by dragging it onto the Photos icon in the Dock.

If that does not work, test first with a new, empty Photos library, to check, if Photos is working at all. To create an empty Photos library, launch Photos with the alt/options key held down. Select to create a new library from the panel, that will appear.