QuickBooks Error 40001 happens when a request cannot be processed by the software, usually because of a server difficulty, a network issue, or corrupted data. Operations like payroll or transaction updates may be hampered by this problem. Usually, fixing it entails correcting firm files to return to regular operation, updating QuickBooks, or verifying internet access. Dial 1.855.738.2784 to talk to a knowledgeable QuickBooks phone support representative.