I had this interesting issue lately on Windows Server 2008 R2 where the shared printer just vanishing from the directory/shares on and off. Here is what I did to resolve this issue.
If you do not have the Print Server role installed, you will need the Print Management Tools to actually view all your printers. You can get the Print Management Tools without installing the role using the following command :
dism /online /enable-feature /featurename:Printing-AdminTools-Collection
Now you can invoke the console using the following command :
printmanagement.msc
Then do the following procedure :
1. Delete the printer.
2. Open the registry editor and search for the exact name of your printer network sharing name.
3. Then do a backup of your registry in case something goes wrong.
4. Delete ALL related keys.
5. Reboot your server.
Once rebooted, re-install the printer as you usually do and things should be back to normal. From this point the printer may be still not visible from Devices and Printers but can be managed through the Print Management (printmanagement.msc) console.