adobe digital editions 4.5

[#1]

I'm having an issue opening a text book in the library.  A message pops up that says "Client certificate used with Digital Editions is invalid. You will not be able to use all the features available in this application!" and i dont know how to fix it!

[#2]

I'm having an issue opening a text book in the library.  A message pops up that says "Client certificate used with Digital Editions is invalid. You will not be able to use all the features available in this application!" and i dont know how to fix it!