Hi Tamara. Everything I've read in forums says it works fine. Two things come to mind...apps cannot be "copied" to new OS they have to be reinstalled. So when you set up Yosemite did you reinstall Picassa? Every database like Picasa has a file where the library info is stored. I don't use Picasa so I'm not much help. But from what I gather the file might be called db3 or similar. Maybe when Picassa got set up under the new OS it starts with a new db3 file so in order to use the one you had all your data on you would just have to get that file from time machine and put it in the correct location? that is a guess....
it sounds as if the file should be in: username>Library>Application Support>Google>Picasa3
In order to see the Library under Yosemite you have to make it visible as Mac hides it.
So first follow these instructions
How to show user library in yosemite:
next look in that directory and see if you can find the db3 file that Picasa techies refer to
right click to get info and see when the db3 file was created...if it is not your old date from awhile ago it means you have a new one started and you might have success at just copying the old one out of time machine.
another thought is when you installed Yosemite did you do anything different than under Mavericks or Lion that might have changed the file path structures? Meaning did you change your Home username from Tamaras Computer to Tamaas iMac or some such thing? If so it might mean that the database is having trouble finding the data. In LR there is a way for you to "find missing files" - not sure if a similar tool is available for Picasa or not.
Hope this helps.~joan
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