IPhoto hangs while requesting local print

Question

Hello,
I am using Yosemite 10.10.2, and iPhoto 9.6.
My printer is a SELPHY CP900.
It has always worked for me (using the Share Print or File->Print as well as ⌘ + P).
But lately I get stuck on the "Spinning Beach Ball of Death" when requesting to print a photo.
Tried all the possible rebuild of the iPhoto Library (177 Gb, 33.745 Photos) using the ALT key at startup, without success.
This is the message I get in the console.
iPhoto[696]: NSProButtonCell: attempt to decode an unrecognized element (0)
Hope someone can help.
(Also tested a new empty library, and this works ok)

Answer 1

Since the new library was able to print OK the problem lies with the old library.  Also since you've tried all of the First Aid options give this a try:
Using iPhoto Library Manager  to Rebuild Your iPhoto Library
1 - download the demo version of iPhoto Library Manager and launch.>Click on the Add Library button,
2 -  select the library you want to add from those in the selection window.
3 - make sure that in the rebuild window the checkbox  "Scavange orphaned photos" is checked.
4 - now that the library is listed in the left hand pane of iPLM, click on your library and go to the Library ➙ Rebuild Library menu option
5 - in the next  window name the new library and select the location you want it to be placed. Click on the Create button.
Note 1: This creates a new library based on the LIbraryData.xml file in the library and will recover Events, Albums, keywords, titles and comments. However, books, calendars, cards and slideshows will be lost.
Note 2:  Your current library will be left untouched for further attempts at a fix if so desired.