iPhoto keeps rebuilding the iPhoto library thumbnails

Hi

A user recently purchased a new MacBook Pro (Mavericks)

I transfered her files and photos, that had been backed up to an external drive, to the new system

Recently she called me because every time she opens iPhoto the application begins to recreate the thumbnails. This process lasts for hours (she has quite an extensive library of pics) and never seems to succeed.

Is this normal behaviour for iPhoto ?

Should we split her library up, or archive some of her photos ?

thanks
yann

Might be a permissions issue.

Try launching iPhoto holding down the command and option buttons, checking every box in the resulting dialog, and letting it do its thing. (this will take a while).

That should fix it.

Thanks chas_m
I believe we did that but I will try again
someone suggested that it might be because icloud is set to sync photos

That shouldn't have anything to do with it.

Possibly the thumbnail database is corrupt, you might have to create a new (blank) iPhoto library and then import the "old" library into it.