When QuickBooks Desktop will not open a company file in multi-user mode, the message on screen decides what to do next. Different errors have different causes, and a fix for one can do nothing for another. This page is a starting point: match your symptom to the right guide, then run the quick checks that apply to nearly every multi-user problem.

Start With What You See

• Error H202. A workstation cannot reach the company file on the server. See QuickBooks Error H202 and H303.
• Error H303, H101 or H505. A workstation is set up to host the file when only the server should. The same guide covers the fix.
• Error -6000 with a second number (-82, -106 or -83). QuickBooks cannot open, restore or back up the file. See QuickBooks Error -6000, -82 and -6000, -83.
• The file opens but is very slow. That is a performance problem, not a connection error. See Why Is QuickBooks Slow in Multi-User Mode?
• Nothing opens and no code appears. Work through the checks below.

Five Checks That Apply to Almost Every Multi-User Problem

1. Only one computer should host. The computer that stores the company file hosts multi-user access. On every other computer, open QuickBooks without a company file, choose File, then Utilities, and if you see Stop Hosting Multi-User Access, select it. Several multi-user errors come from a workstation that is also trying to host.
2. Database Server Manager must be running on the server. It is the program that manages access to the file, and it runs as a service named QuickBooksDBXX. If the service has stopped, workstations cannot connect. Our guide to Database Server Manager explains how to scan the folder and check the service.
3. The server must be awake. The server computer cannot be asleep, restarting or switched off while others work. Set its power options so it never sleeps. This is general advice, not an Intuit rule.
4. Check where the file is stored. Intuit says Database Server Manager does not support Network Attached Storage (NAS) devices. A company file kept on a NAS will cause multi-user trouble even when everything else is set up correctly.
5. Check the network. From a workstation, ping the server by name. Replies with no lost packets mean the path works. Lost packets or very slow replies point to a network problem that needs an IT professional. As general advice, a wired connection is more dependable than Wi-Fi for a shared company file.

Run Intuit’s Tools

If the checks do not solve it, use the QuickBooks Tool Hub on the server. Under Network Issues, run Database Server Manager and scan the folder with your company file. Then, under Company File Issues, run File Doctor and choose Check your Network. Intuit recommends these before any manual fix.

What Not to Do

• Do not copy the company file to each workstation to get around the error. Work in one file, on the server, so everyone sees the same data.
• Do not turn on hosting on several computers to see which one works.
• Do not skip a backup before you rename, move or repair files.

If It Keeps Happening

Recurring multi-user problems usually mean the company file is sitting on office hardware and a network that weren’t built to run it reliably. Cloud hosting removes that constraint — multi-user mode works exactly the same way, but the file lives on infrastructure built to stay online, with no single host machine required. See the full breakdown of why this happens. For how a hosted setup works day to day, see How to Set Up QuickBooks Multi-User Mode.

Related: QuickBooks Error H202 and H303: Causes and How to Fix Them

Source: Intuit’s help articles on multi-user errors H202, H303 and -6000. Steps can vary by version, so check Intuit’s current guidance for yours.