If the Format | Sheet | Unhide does not reveal them, they may be "very
hidden" which is a setting usually made from within the VB Editor. But you
can unhide them using VB code easily enough:

Sub UnhideEvenVeryHiddenSheets()
Worksheets("Sheet3").Visible = True
End Sub

change the sheet name as needed, repeat the line of code for each sheet you
need to unhide. I would make a copy of the original file before messing with
these sheets, especially if they are very hidden. The developer obviously
didn't want anyone messing around with them because they are critical to
operation of the visible sheets.

Also, formulas enclosed in curley braces as {} are array formulas, the {}
are not typed in, they are placed around the formula when you enter the
formula with [Ctrl]+[Shift]+[Enter] instead of just the [Enter] key. Any
editing of such a formula requires using that key combination to restore the
curley braces.

"surreyjed" wrote:

I have been sent a file with cells that contain formulas that are delimted
with {} and refer to sheets that are not present. If I try to create sheets
with these names I am told that they exist. Hence a hidden sheet. Any help on
hidden sheets and {}?