Remove Deleted Files From History (CmdRemoveDeletedFilesFromHistory, command palette) removes files that no longer exist on disk from the list of recently opened files.

With ReuseInstance, opening a file uses a SumatraPDF window on the current virtual desktop, or opens a new window there, instead of switching to another desktop (#5630).

In ExternalViewers command lines, %% stands for a literal %, e.g. %%d is passed to the program as %d (#5583).