Excel Gurus,

Can you please explain the meaning of this error? I am getting this error in a workbook that I developed. I used CustomUI Tab in the workbook.

In very rare cases and when opened in Office 2007, I noticed this error popping up (and if this error pops, the tab is not being displayed). I would be greatful if you can explain what might be going wrong.)

error.PNG

Regards,
RK.