If your plans for the long weekend (in the UK and US) included the prospect of trying out some fresh Windows 10 features with the new preview version, then sadly youll have to think again, because Microsoft has delayed the build that was expected to be released this week.Dona Sarkar, head of Windows testing at Microsoft, took to Twitter to announce that a preview build wouldnt be rolled out this week because some rollback issues had been discovered.Rollback issues simply refers to problems that are big enough to require a rollback or reversion to a previous state, so the team can work on solving the bugs from scratch with a fresh approach rather than trying to fix whats there.That takes more time, and with the holiday weekend meaning staff are wanting to spend time with family as the tweet mentions, theres no chance of the release of a new build this week.Bit of a waitNo timeframe was mentioned as to when this fresh test build of Windows 10 will eventually emerge, but we might be in for a bit of a wait from the sound of things.As MS Power User, which spotted Donas tweet, observed, this incoming build is expected to work further on Sets and deliver some other new features to boot.Microsoft has been working hard on Sets which brings the concept of tabs from the browser to the wider operating system in general in the last couple of preview builds.The company plugged this feature heavily at the recent Build conference, where Joe Belfiore detailed the overall vision for Sets, which is all about making Windows 10 a much easier, more streamlined experience when it comes to finding related content and the things you need.