05-20-2018, 10:48 AM
There were large changes in Windows for the Spring Update 2018. Among them the whole Homegroup thing was removed, and they just went back to the original scheme of sharing folders and such. Somewhere in all of that, they seem to have introduced a bug that affects name resolution, i.e. the ability of programs to convert a machine name to its network address. 
This bug manifests itself in a few ways:
1. You cannot connect to the machine except using a particular upper/lower case combination of characters. So the actual machine name (which is often mixed case as entered by the user) won't work. Sometimes only all upper case will. Sometimes only all lower case will. Even just trying to ping the machine using the simple command line ping will fail based on case. It's a fundamental truth that name resolution is not case specific, so this indicates that there is a major bug.
2. Sometimes the ability to resolve the name is sporadic. This might lead you to think that this or that fix or change worked, when really it didn't, and it will fail again later. Or, for all we know, the actual versions of the name that will resolve correctly at any given time is changing. But clearly there are sporadic issues as well.
3. Other folks are finally starting to report this besides us, and some of them are also seeing it at the Windows networking level. So they will have trouble accessing other machines reliably in the Network section of the Windows explorer, sometimes they show up, sometimes not. This apparently is a manifestation of the same issue, and would tend to argue towards the sporadic failure scenario.
With CQC, it generally means that you will get 'Unable to convert host name x to an address' type errors. It might happen during the installer, if you entered the MS host name in a case that isn't working for you now. If that works, you will likely have an issue running other programs because the MS will advertise its services using the name that the OS there on the MS reports, and that will typically be the name as you entered it when you set that machine up. That may be the least likely format of the name to work.
So, it would seem that it would likely be a good thing to hold off on the 1803 upgrade. You can lock out upgrades for up to 30'something days, so you probably should do that. Hopefully MS will get this fixed and update the update and then you can let it go.
* BTW, you may have no problems. Some do, some don't. If you have already upgraded, and it's working fine, the probably you are OK. What actually causes it to happen is unknown, that I've seen. But it's not a universal failure or anything. There's something about some systems that makes it happen.
This bug manifests itself in a few ways:
1. You cannot connect to the machine except using a particular upper/lower case combination of characters. So the actual machine name (which is often mixed case as entered by the user) won't work. Sometimes only all upper case will. Sometimes only all lower case will. Even just trying to ping the machine using the simple command line ping will fail based on case. It's a fundamental truth that name resolution is not case specific, so this indicates that there is a major bug.
2. Sometimes the ability to resolve the name is sporadic. This might lead you to think that this or that fix or change worked, when really it didn't, and it will fail again later. Or, for all we know, the actual versions of the name that will resolve correctly at any given time is changing. But clearly there are sporadic issues as well.
3. Other folks are finally starting to report this besides us, and some of them are also seeing it at the Windows networking level. So they will have trouble accessing other machines reliably in the Network section of the Windows explorer, sometimes they show up, sometimes not. This apparently is a manifestation of the same issue, and would tend to argue towards the sporadic failure scenario.
With CQC, it generally means that you will get 'Unable to convert host name x to an address' type errors. It might happen during the installer, if you entered the MS host name in a case that isn't working for you now. If that works, you will likely have an issue running other programs because the MS will advertise its services using the name that the OS there on the MS reports, and that will typically be the name as you entered it when you set that machine up. That may be the least likely format of the name to work.
So, it would seem that it would likely be a good thing to hold off on the 1803 upgrade. You can lock out upgrades for up to 30'something days, so you probably should do that. Hopefully MS will get this fixed and update the update and then you can let it go.
* BTW, you may have no problems. Some do, some don't. If you have already upgraded, and it's working fine, the probably you are OK. What actually causes it to happen is unknown, that I've seen. But it's not a universal failure or anything. There's something about some systems that makes it happen.
Dean Roddey
Explorans limites defectum
Explorans limites defectum