Blender Operation Success or Failure Feedback? Sometimes when I try to apply an operation in Blender (e.g. Mesh > Faces > Tris to Quads) nothing seems to happen (similar to here). I wonder whether I selected the correct operation, or what else I might be doing incorrectly.

Is there a way to see any feedback on the success or failure of an operation? I'm used to software (such as Rhino), that puts useful messages in the command line after each operation like "3 meshes joined" or error messages explaining why the operation failed.
F6 (operator properties)

Operators may still be active, if you press F6 after noticing a seemingly 'no-op' operator you can get a chance to tweak parameters.



Info Panel (Operator reporting)

As a rule you will get some kind of confirmation that an operator has completed, you could drop down the Info panel to see any output printed by the operator.



Terminal / Console

For more verbose messages sometimes operators print to the Command window, on windows this can be opened while Blender is running ( Window > Toggle System Console). On osx or linux Blender needs to be started from a terminal to get the print-outs.

Windows users be warned
Don't close the Console window manually using the X, that will close Blender. To close the System Console, click the menu item at Window > Toggle System Console again -- that will toggle the console off.