I'm mystified as to why this happened, but I'm hoping someone can help me fix
it in an easy way...
I have a workbook with multiple sheets, and many buttons with assigned
macros on different sheets for navigation, filtering, etc.
I created a new blank sheet within the workbook for a throwaway calculation,
and then decided I didn't want it in that book so right clicked and moved to
a new book. That was fine and I proceeded with my calculating for a while.
Then I went back to the original book and tried to use a button, but got an
error that the macro did not exist, referencing 'Book12', the new book
created with my calculation sheet. I figured something odd had happened with
moving the sheet, so I moved it back again, but now clicking a button gives
me 'Book12.htm cannot be found...'

I really don't want to have to go through each one and reassign all the
macros one at a time - is there any way of fixing this straightforwardly?

Note: The macros themselves are saved in a module within the workbook, not
on any individual sheet. This is what makes the whole thing so odd.
Removing the 'Book12!' from the start of each reference makes it work fine
again.

Thanks in advance for any help!