If you are using a Maven mirror / proxy (e.g. a Nexus as a proxy for Maven Central / Alfresco Artifacts), then it could be that you have an issue with a cached archetype catalog. The mirror / proxy scans any repositories backing it and builds a local, aggregated archetype catalog. If the mirror / proxy does not automatically re-scan those repositories, that catalog can get out-of-date and not expose the newer versions of the SDK. I myself had this problem with my local Nexus proxy that I use to cache most dependencies, and had to manually tell my Nexus to re-index all the backing repositories, and afterwards the local catalog worked fine so that I could select the expected SDK version.