Judging from the stack trace, you are using a localization file which incorrectly defines the collectioncount.nonzero.format entry.
Please post the respective line from the localization file here.
EDIT:
Here is the default, and correctly formatted, value:
Code:
collectioncount.nonzero.format={0,plural,one{# item}other{# items}}
The error message indicates that you are using something like
Code:
collectioncount.nonzero.format={1...
... which is indeed wrong, and will indeed crash the program - as you noticed