Lyx Can’t Apply Change to Document Settings


Whenever adding a new file, document->settings can’t make any change as the “Apply” and “OK” button are grey out. Also, there is error: “Package keyval Error: No value specified for tab.” with Description below: “\lstset{tab}  Try typing <return> to proceed. If that doesn’t work, type X <return> to quit”, whenever the document is viewed as pdf.


Go to Document->Settings->Listings, delete the devil “tab” under the “Parameter tab: A value is expected.” window. It’s better to also click “Saved as Document Defaults” at the bottom otherwise the same error occur whenever a new file is created.


  • When surfing the web, most (if not all) not say that it’s impossible or there’s a bug.
  • Document change can be made except Document Settings, even saving as another file is fine.
  • Even nothing is typed into the document, whenever you view it, the same error will appear.
  • Probably input wrong Document->Settings->Listings parameter “tab” and had pressed “Saved as Document Defaults” unexpectedly.
  • Even though without the wrong parameter “tab” input in Listings, user had to first select a “Document Class” as soon as a new file is created otherwise user cannot change any other Document Settings by having all the “OK” and “Apply” grey out.