Access - can't save objects, says I need exclusive rights to the file

I have a client I'm helping with a database.  There are about 12 people who use this file.  The file is split into front end and back end.  All employees access the same front end.  They are trying to create a new query or report, but are given the error message "Microsoft Office Access can't save design changes or save to a new database object because another user has the file open.  To save your design changes or to save to a new object, you must have exclusive access to the file".  

Nobody is opening the file with exclusive rights, and to create a simple query, they don't need this.  Any help is appreciated.  Thanks!