This error has caused me so much pain when trying to use SharePoint’s JavaScript client-side object model (CSOM), so, in case I have it again:
- Check that the function exists.
- Check that the function is named correctly.
- Make sure that you’re not using “this” in the call to createDelegate, as detailed here.
- Right:
Function.createDelegate(this, onSuccessMethod) - Wrong:
Function.createDelegate(this, this.onSuccessMethod)
I don’t know why this difference should cause this error, but I’ve proved it true.
- Right:
If you know of other causes of this error, let me know, I’ll add it to the list. I love the experience of debugging JavaScript…
Andy Burns' Blog 
I have also had the error message “Unable to get value of the property ‘apply’: object is null or undefined” which had the same cause.
Thank you so much 🙂 ur post was just the thing i was looking for.. spent two days on this issue..
Totally agree with Anusha, Thanks!!
Thanks a lot . I was facing same issue .
One more thing ,though it has given this error , item was created successfully.