Steps to fix QuickBooks error 6000, 100 are:

Solution 1: toggle the hosting mode.

File-Utilities-stop hosting multi-user mode. After that try  to open QuickBooks, If you continue to get the same error proceed with solution 2

 

Solution 2: rename .nd file.

  • Locate the .nd files with the name of the company having trouble opening & rename it to something else & try opening QuickBooks.
  • If you continue to get the same error proceed with solution 3.

Solution 3: (only if you are running NOD32 Antivirus Software)

  • Open NOD32 antivirus & disable IMON functionality.  Once done restart the computer & & open QuickBooks.
  • If you continue to get the same error proceed with solution 4.

Solution 4: run reboot.bat.

  • Open the folder containing the reboot.bat file:
  • · Windows 8, 7 or Vista:
  • Right-click the QuickBooks icon on your desktop and select Properties.
  • Click Open file location.
  • · Window XP:
  • Right-click the QuickBooks icon on your desktop and select Properties.
  • Click Find Target.
  • Right-click on reboot.bat and choose Run as the Administrator.  Note: This step is important, you need to run reboot.bat as Admin.
  • Check to see if this resolves the issue.  If not, reboot your computer.
  • If you continue to get the same error proceed with solution 4

Solution 5: Go for a clean install.

Note: Before going for a clean install make sure that the file is not damaged by opening a sample file. If you continue to get the same error -6010 -100 while opening sample time too, then proceed with clean install & if the sample file is opening fine it means that it’s a data problem & you need to contact data service.

If you want any information related to QuickBooks then you can call us QuickBooks  Error support phone number +1-855-441-4417.

Reference: http://www.askproadvisor.com/question/how-do-i-fix-quickbooks-error-6000-100/