Cura 4.1 and 4.2.1 stopped seeing UM3 on LAN

[johnse 31]

I've been happily printing with my UM3 for quite a while. One quirk of Cura seems to be that if the printer is not on when I start Cura, Cura will never see that it is online. I have to close Cura and restart it for the UM3 to show as online.

 

That has been a constant until today. Today, no matter how many times I restarted Cura, it would not acknowledge that the printer was online. This started with Cura 4.1. I then installed Cura 4.2.1 to find the same behavior. I pinged the printer and it responded as expected.

 

Following the Network Troubleshooter, I removed the printer. I then tried to re-add it and it was not discovered on the network. I was able to manually add it by IP address.

 

The initial problem of not seeing the printer was happening before I rebooted to complete installation of Windows Update:  https://support.microsoft.com/en-us/help/4512508/windows-10-update-kb4512508. It is possible that the update had left the computer in a wonky state until the reboot.

 

I'm in a working state now, so this is more of a heads-up to the developers...and also a query if anyone else has had the first issue of only seeing the printer if Cura is started while the printer is on (I.e. start Cura with printer off, then turn printer on, Cura will not recognize this fact.)O 

 

[nallath 1,124]

We use zeroconf for the automatic discovery. Microsoft has had a very bad track record with breaking it in windows.

 

If the IP's on your network don't change often, I'd recommend just using the add printer by manual IP option.