Sierra unable to update.

Tell us more, we need to know what MacBook Pro you have, model and age, you will get this from About This Mac.

Are you trying to update an existing version of Sierra or are you trying to upgrade your MBP to Sierra from an earlier OS or are you trying to upgrade to High Sierra.

So come on give us a bit more of a chance to help you.

Thank you for your fast response. I have finally managed to update OSX to the final version 10.13.4, still not sure what the issue was but no need to bother you further 🙂