Unable Access Rapid Board if Story Point is Edited/Set in German(Germany) Language.

In the GreenHopper Rapid Board the systems shows an empty screen with a message:

Error
'00000000000005.000' is an invalid number

The given number changes depending on the project:

Error
'00000000000013.000' is an invalid number. 

Caused by:
Rendering of values now follows user locale. German locale differs from Swiss and English locale in that it uses comma instead of dot for decimal values.

Workaround:
Change the user's locale back to English to keep the Rapid Board working