Why does the back button become unavailable after awhile?

[Cvance]

I am working on a visio document and I have the undo options set to the
maximum of 99 and the recently used file list set to the maximum of 9. I do
not have the access to make any more undo's. If I have reached 99, how is
this reset? I have closed document and re-opened, but still not reset. I
need to finish my visio but am not comfortable without the undo button
working.

 

[Paul Herber]

I am working on a visio document and I have the undo options set to the
maximum of 99 and the recently used file list set to the maximum of 9. I do
not have the access to make any more undo's. If I have reached 99, how is
this reset? I have closed document and re-opened, but still not reset. I
need to finish my visio but am not comfortable without the undo button
working.

Why on earth do you need 99 undo levels? Whatever you set the undo
level to it will always provide the latest n undo items, the old items
get pushed off the end of the list.

 

[mikeFin]

It is true, that the back button becomes unavailable after a while. This
happened already 2 or 3 time to me.
I am not sure, but perhaps it happened while I had the ShapeSheet opened,
and waited for a while, then the undo button became gray after a while.

 

[Paul Herber]

It is true, that the back button becomes unavailable after a while. This
happened already 2 or 3 time to me.
I am not sure, but perhaps it happened while I had the ShapeSheet opened,
and waited for a while, then the undo button became gray after a while.

Yes, you are right, it's not anything to do with the Back button
though, it's the Undo. Back is something else completely.

I can repeat this by having a diagram (1) containing a shape with a
hyperlink to another Visio diagram (2).
1. Move the shape or add a new shape to get something into the undo
system.
2. Follow the hyperlink to diagram (2). Close diagram (2). You are now
back at diagram (1) and all the Undo information has gone.

Doing a plain open on document (2) then closing it doesn't lose the
undo info.