Macro will not run

When one of my workbooks is opened, a macro runs that opens, saves, and closes four other workbooks. This workbook is opened daily and I have been using this macro for about 4 months now. Starting two days ago the macro is not running anymore. Does anyone know why this could be happening? All of my macros and workbooks are protected so no one else could have changed it. Is there an option that may have disabled it somewhere? Thanks for your help.