If you get an error message in Excel you might not get much help from the program in finding out the cause. The articles listed here cover the cause and cures for a number of common error messages in Excel, such as #REF!, #NULL!, and #####.
Excel #REF! Error Message
An invalid cell reference error message occurs when a spreadsheet formula contains incorrect cell references. This article covers how to correct this error in Excel.
Excel ###### Error Message
Sometimes referred to as “Railroad tracks”, this condition is not really an error, but it occurs frequently and it can be frustrating if you don't know what it is or how to fix it.
Excel #NULL! Error Message
A #NULL! error message occurs when the two or more cell references are not separated correctly in a formula. This article covers situations when this error will occur and how to correct it.
Excel #DIV/0! Error Message
A #DIV/0! error message occurs when a formula tries to divide by zero. This article covers situations when this error will occur and how to correct it.