IWP

I upgraded my s5 firmware to the 5.4.6 (as advised by Cura) and then started having real problems with the printer stopping and telling me it had run out of filament, when it hadn't. When I tried to change the filament it stopped halfway through retraction and made a horrible noise. After contacting my supplier they advised me to rollback to 5.2.11which I did. Since then the latest print has lots of stringing and small strands of filament all over it. (see picture). It did seem to reduce the amount of times it stopped because of flow sensor but when it did it still made the horrible noise when changing. Any ideas???

Hi I have just purchased an Ultimaker s5, I tried to set up the Wi-Fi on it but all the buttons were greyed out. I returned it to the supplier and he checked it reinstalled the software and returned it to me. The same problem still exsists. Everything else is fine and it is printing well. I have a 4 day 19 hour print on it at the moment. Any ideas what could be causing the problem with the Wi-Fi???? as I do not want to have to return it again. I live in the UK. Thanks