Google shut down Picasa Web Albums on May 1, 2016, and as of March 15, 2016, it will no longer support the Picasa Desktop application.
Tip: we always recommend being in charge of your own digital files. In case that favorite application of yours someday becomes like Picasa. At times we cannot avoid having online photos. However, it's always best to buy three external hard drives.
One to be your master archival copy and keep it outside the house. Perhaps get a bank vault and add the hard drive along with your other precious items.
The second one to be the backup of your master archival: at the end of each month upload all your digital files that you want to keep.
The third external drive to have digital files that you like to access often for sharing or further working with.