Error: ***The value for "hamburgerCallback" must not be undefined

Iron Contributor

Did I forget the mayo? Is it not well-done enough?


What does this even mean?


My project now gives me this error seemingly out of nowhere.  It occurs before the Workbench even finishes loading.  If anyone's got any ideas,  I sure would like to hear them.

4 Replies

Same here. Last night (NZ time), everything worked, this morning I get those two exceptions about hamburgerCallback and InvalidOperation. I am  using MS Code and am developing an SPFx client webpart. I run it on the host-workbench: . After "ignoring"/F5 the exceptions, it seems to run sweet.

Error: ***The value for "hamburgerCallback" must not be undefined
at Function.e.isNotNullOrUndefined (
at e.get [as hamburgerCallback] (
at e._onRender (


Error: Sys.InvalidOperationException: Operation is not valid due to the current state of the object.
    at Function.Error.create (
    at Function.Error.invalidOperation (
    at Function._o365cl.a.b (
    at _o365sg2c.r.b.f (
    at _o365sg2c.r.a (
    at Function.O365Shell.InvokeSuiteAPILoaded (
    at _o365sg2p.Loader.h (


Me too. Can't debug in a hosted work bench. 

@David Palfery and @Dennis Kuhn,


Thanks for the notes, fellas.  Always a relief to find out "it's not just me."


Off to cross-post at SP Dev Docs so that it can be heard by someone with a snowball's chance of getting something done about it.



Good to hear indeed that there's others out there ;) First I created an issue at vsCode, they redirected me to the Chrome debugger extension, so the issue is there now: