If you want to find answer to question - why this cell produces error value,
this command will help you. Trace error command will analyse all precedents of
formula in-depth. And only cells, which are at the beginning of the error
chain, will be filtered and shown. So, you will see only sources of error, not
a long chain with errors, which could contain more than 1000 levels on a large
To analyse why cell contains error use
Evaluate cell command in context menu. It will show values of each
sub-expression in formula. You should only find which of them contains error.