Comment 1 for bug 1575248

The AppStream component 'com.steelseries.rival-legacy.firmware' in `/usr/share/app-info/xmls/org.freedesktop.fwupd.xml` must have a <name/> and <summary/> tag to be valid.
Adding fwupd, because this should be fixed there. Upstream said he will commit a fix to fwupd tomorrow.

The ID collisions are issues in the metadata Ubuntu provides, and something which can only be fixed server-side, or basically in the packages providing:
 * plan.desktop
 * flcheckers.desktop
 * flblocks.desktop
 * flsudoku.desktop
If two packages providing the same .desktop file is justified, one should be ignored using X-AppStream-Ignore, so it is clear which one is the primary component to be used by AppStream.

The issue "zathura-pdf-poppler.desktop extends zathura.desktop, but zathura.desktop was not found." needs to be investigated, looks like there is some package/file missing in the archive, or a value isn't set correctly.

In any case, fixing the fwupd issue will make the warning message go away, so I'm marking this as invalid on AppStream for now.