It sound like you are creating and destroying the toolbar at the workbook
open events. I assume you are destroying the toolbar when you are done.
Instead of using this even try using the AddinInstall event something like
this... This way your toolbar does not need to be loaded each time and
perhaps your onaction will not have the conflict.

Private Sub Workbook_AddinInstall()
Call CreateMyToolbar
End Sub

Private Sub Workbook_AddinUninstall()
Call DestroyMyToolbar
End Sub
--
HTH...

Jim Thomlinson


"Josh Sale" wrote:

No ... a single copy of the add-in in each instance of Excel.

At startup, the add-in creates a few toolbars and puts a number of buttons
on each one. So there is a period where maybe 20 or 30 toolbar buttons,
shortcut menu's, etc have their OnAction property set. And this is where it
blows it brains out.

josh



"Jim Thomlinson" wrote in message
...
Multiple instances of excel running should not (to the best of my
knowledge)
cause any difficulty. Each one resides in it's own world and does not
interact with other instances. In any one instance of Excel do you have
the
addin running more than once (I might be a little slow on the uptake but I
could not determine that from your post)?
--
HTH...

Jim Thomlinson


"Josh Sale" wrote:

Jim,

We're actually running multiple instances of Excel and the add-in
intentionally. We have a non-Excel process runs on a server and that
reads
messages off of a queue. Depending on the content of each message this
process spawns off a copy of Excel with command line arguments that are
based on the message content.

So we want to make this work.

The add-in isn't added by code.

josh



"Jim Thomlinson" wrote in message
...
My question is how are you getting two instances of the addin running
on
one
machine concurrently? Solve that and the problems go away... Is the
addin
installed through code?
--
HTH...

Jim Thomlinson


"Josh Sale" wrote:

I have an add-in that works just fine when there is a single instance
of
it
running on a particular machine.

However, if two copies get launched at essentially the same time on
the
same
machine, I get the following error:

Method 'OnAction' of object '_CommandBarButton' failed.

The runtime error number is 80004005. The failing line of code looks
like
this:

Dim cmdButton As CommandBarButton

cmdButton.OnAction = "SomeMacroName"

Again, the assignment statement and the resulting toolbar button work
just
fine when a single instance of Excel and the add-in is running ... the
error
only happens when two copies are started at the same time.

Any thoughts?

Do multiple copies of Excel share something that's causing this
problem?

BTW, am running XL2003.

TIA,

josh