For a couple of days I notice no Leap 15.0 repositories are available. Entering zypper up results in the following (example):
Repository 'Qt 5' is invalid.
[Qt_5|https://download.opensuse.org/repositories/KDE:/Qt5/openSUSE_Leap_15.0/] Repository type can't be determined.
Please check if the URIs defined for this repository are pointing to a valid repository.
Warning: Skipping repository 'Qt 5' because of the above error.
The same applies for various other repositories such as Frameworks, KDE and others.
Am I missing something.
You missed probably the fact that 15.0 is out of support (and that is also the reason that you had to choose OTHER VERSION from the thread title prefix).
Download the 15.1 DVD and upgrade. Although an online upgrade using “zypper dup” will likely work, without a DVD if something should go wrong you might have difficulty recovering… So, use the DVD method.