Bitstarcoin v2.5 (barterdex compatible update)
None Mandatory update but is recommended
Download: https://github.com/bitstar/bitstarV2.5/releases/tag/v2.5.0.0
Source: https://github.com/bitstar/bitstarV2.5

Please note wallet.dat is not compatible with v1 and v2.0 (due to using a much newer libdb database), you would need to importprivkey or wallet