What might cause failure of 'Sort' operation?

I cannot sort using single or multiple options (or none) for file of 900 rows and 6 columns, although previously the file sorted without problems. All the fields in this file are linked to primary entries in another separate file. There are no merged fields in either file. The sort operation still works properly for other files.

And “cannot” means … what happens?

Please do not use the Answer field, edit your original question to provide further details. Thanks.

Nothing happens. There is no change in the order of the entries in any column.

You might have formulas setup such that the result is always equal… anyhow, without the document in question there’s nothing to say.

Problem is resolved thanks to your comment about formulas setup, which led me to find that several of the source file numeric entries somehow were entered as text. Thank you.