QuickBooks Error 6123 | Five Effective Solutions to Fix. Get to know more about the error and try fixing it with our customer service! No doubt, QuickBooks is the leading accounting software as it manages all the financial information of a user and helps them create invoices, balance sheets, and bills efficiently but it might be horrifying to get an company file error in QuickBooks as it contains all the crucial information of a business. An error that QuickBooks encounters while setting up multi-user access to a company file is Error 6123, 0. Once you get QuickBooks Error 6123 (855)756-1077 , QuickBooks displays an error message “An error occurred when QuickBooks tried to access the company file. Please try again. If the problem persists, contact Intuit® and provide them with the following error code: (-6123,0)”. Thus, QuickBooks Error 6123 is an error that occurs when you try to open or work with your company file. This typically happens when the file is corrupted, but it can ...