A family of Microsoft relational database management systems designed for ease of use.
When an object stops functioning as expected for no apparent reason the first thing I always do is to copy the object to the clipboard, and then paste it in under a new name. This almost always cures any corruption which the object has incurred. So, I'd try that first with your macro. If it still raises the error, then you need to look for a semantic error of one of the types described by George. If not, delete the original macro and rename the copy back to the original name.