Import SDK Extension in DS 1.4

Helo,

i am trying to going through the Developer Guide and make the first extension (3.3.5 page 16)

but i am getting following error after restarting DS:

A problem occurred while parsing a Design Studio Extension XML (path "contribution.xml" of extension "null", line 7, column 15): cvc-pattern-valid: Wert "1.0.0" ist nicht Facet-gültig in Bezug auf Muster "\d+\.\d+" für Typ "#AnonType_versionExtension".