This short list has been a great help in learning VBA. When trying to debug an object reference error, do the following:
1. Look in the Object Browser for exactly the object, method, or property that is reported to fail in the error dialog.
2. Think about what the object reference is trying to do, and how VBA is parsing it.
3. Check the help on that topic, especially the "Applies To" section. Jump to the "Properties" and "Methods" sections to be sure the reference is valid for the object—and stare at the code for a while (those with more experience will spend less time here.)
4. If unsure of the mistake after checking Help, try writing a very simple example in a blank worksheet to explore what may be wrong. This can be a great tool for getting things clear quickly.
5. After doing these four things, only then is it a good idea to change the code to work with a different object, method, or property. Doing this too soon may create more confusion!
Remember: Look, Think, Check Help, Simple Example...Then, change the code!