Can't access migrated photos in IPhoto

I recently had to migrate photo's from backup into iPhoto,

How did you do that? What kind of backup?

Did you restore an iPhoto Library from a Time Machine backup by running Time Machine? Or did you copy an iPhoto Library from another kind of backup?

The blurry photos may be caused by permission issues.

Try all first Aid options for your iPhoto Library, starting with "Repair Permissions".

See Old Toad's post here on how to rebuild or repair the iPhoto Library:

iPhoto has crashed on a number of occasio… - Apple Community