Numerous reasons contribute to the occurrence of . QuickBooks components or files may be corrupted or missing. MSXML is a critical component supplied by Microsoft that the QB application needs. This file is critical for obtaining the information stored in the QBregistration.dat file. An explanation may be that you're using an older version of the Windows operating system. The most current version of QB may be incompatible with older versions of Windows. There may be some network connectivity problems.