Well, to fix the error 6155 in QuickBooks, one of the most successful techniques is to do a clean installation of QuickBooks. This process will wipe out the application completely and will install it again such that it is free of any issues or errors. The steps to perform the clean install are as follows:
First, press the Windows + R keys and type appwiz.cpl in the text box of the Run window you get on the screen.
Then, click OK and look for QuickBooks in the list of given applications.
Now, click twice on the application and select Uninstall.
Thereafter follow the on-screen instructions and remove the QuickBooks Desktop application completely.
Later, download and install QuickBooks Clean Install Tool.
And follow the instructions that it displays on the screen to install the QuickBooks application again on your computer.
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