Simple Steps to Resolve QuickBooks Network Diagnostics Failed Issue When QuickBooks is unable to identify or fix network connectivity problems, the error QuickBooks Network Diagnostics Failed appears. It typically shows up when a company file is accessed in multi-user mode. This issue, which hinders seamless communication between QuickBooks and the server, could be caused by misconfigured hosting settings, firewall restrictions, or a broken network configuration. Call 1.855.738.2784 to speak with a QuickBooks specialist. Read more : https://accountinghelplinesupport.weebly.com/blog/quickbooks-network-diagnostics-failed-complete-step-wise-methods