Situation: This message may appear for a number of reasons. Possible causes might be that the company file is locked, access privileges for the company file may be incorrect, or there may not be enough room on the hard disk where the company file is stored.
Solution: Check to see that you have given full (read/write) access to the folder where your company file is located.
If you have very little room on the hard disk where your company file is stored, remove some items from the hard disk. You may also want to consider increasing the size of the computer's hard disk, since your company file will probably continue to increase in size over time.