Currently I am working in a small firm, and the attached error keeps poppoing up on a particular set of drawings. The thing is, it happens even when the file is not opened by other employees. In other words, if I am the only one in the office, and I want to work on the CD set, I have to get past this 'xlsx is locked for editing' message that appears even when no one else is in the file. Does this make any sense, and are there any suggestions how to fix the problem?