If user has bg=NONE or bg="" on any of the four groups...

[averms]

The Restore functions will throw an exception, and the ones after the one that throws an exception will not get executed.

lite-dfm/plugin/litedfm.vim

Lines 143 to 152 in 9420ab6

   try 
     execute s:Restore('LineNr') 
     execute s:Restore('CursorLineNR') 
     execute s:Restore('NonText') 
     execute s:Restore('FoldColumn') 
   catch /.*/ 
     " Attempting to Restore values fails when they were never changed to begin 
     " with. This is VimScript, so we don't care and just swallow the 
     " exception. 
   endtry