What Causes of QuickBooks Error 4120?

There might be a myriad of reasons that may cause this error to occur some of which are listed as follows:
•    If an antivirus or security-software has falsely marked any QuickBooks executable file or other components as unsafe.
•    When there is a software change related to QuickBooks, it might cause the windows registry to be corrupted.
•    When any other program deletes files related to QuickBooks either by mistake or otherwise, an error may

If all the given solutions fail to fix the error, you may seek professional assistance. Directly contact QuickBooks Customer Service at toll-free number +1-855-756-1077.