I have two Unity version installed 2017.3.0f3 and 5.6.3p4. The Unity 5 version is displayed correctly but 2017 has what I think is Build number. This causes Hub to ask message that I'm trying to open Unity project that is in 2017.3.0f3 in different version and should it proceed. Screenshot:
Hi @mathewp. We're aware of this issue and its in our plan to address it in the coming Hub updates. In the meantime, I suggest you to remove and reinstall your 2017.3.0f3 (from the Hub this time).