8004041C - An internal QuickBooks error occurred while trying to access the QuickBooks company file. 

See Resolving QuickBooks Connection Errors.

Rebuild your QuickBooks company data file.  From the QuickBooks File Menu ->Choose Utilities ->Rebuild Data. 

This could be a fairly long process especially if you have a large data file.  Do not be concerned if the Rebuild function appears to "hang or do nothing" at 99% during the first pass or at about 50% on the second pass, it simply means that QuickBooks has found problems in your file and is working diligently to correct them.