Thanks, Mike. The question arose this way. I was using a right click to add
sheets. Done it that way many times in the windows version.
In fact, I can use it to number the same type of sheet in a serial fashion
automatically if done that way.
For example, I add a sheet for "Dealer" to the workbook. Next, right-clicking
the tab, I opt to move or copy. When the next one is added, Excel appends a
number to the tab name.
I couldn't get it to copy over 12 in that manner. Thought it might be limited
some way...
There's an internal codenamer associated with the VBA worksheet code
module. In previous versions, copying the worksheet internally added a
'1' to the end of the name (e.g., Sheet2, Sheet21, Sheet211, etc). When
the codename reached the limit of 15 characters, further attempts to
copy would fail.
Note that the codename is not associated with the displayed sheet name
on the tab.
Can't say if that's happening here but if it's only that particular
workbook/sheet, that may be it.