Picasa is now a discontinued application which means that support for Windows 10 doesn't properly exists anymore, therefore this might be the cause to your issues. I recommend running the application on Compatibility Mode using right click on file then Properties > Compatibility. Select a previous version of Windows from the list and then run it again.
The developers have stated that if you downloaded the app and it works this way, then good, but they will not release any updates or fixes for issues.