Other users currently have this company open in multi-user mode" explained
Sage 50 is telling you someone else has the company open, so it will not let you switch to single-user mode.
The message reads: “Other users currently have this company open in multi-user mode, so it cannot be opened in single-user mode.”
Despite the wording, this is not an error and nothing is wrong with your data. Sage 50 is simply refusing to open the company in single-user mode because other people are working in it right now. Single-user mode means one person has exclusive access, and that is impossible while others are logged in.
What the message actually means
Sage 50 can run a company in two ways. In multi-user mode, several people can work in the file at once over the network. In single-user mode, one workstation has the file to itself, which some maintenance tasks require.
When you ask for single-user mode, Sage checks whether anyone else is connected. If it finds even one other active session, it blocks you with this message. It is a lock notice, not a corruption warning.
Why it happens
The most common cause is the obvious one: colleagues genuinely have the company open. Someone may have left Sage running overnight, or a workstation crashed without releasing its session.
Occasionally the block lingers after everyone has closed Sage. A crashed session can leave a stale lock behind, and the program still counts it as an active user. A reboot of the workstation holding the lock, or of the machine hosting the company data, usually clears it.
Ask the other users to close the company
The safest fix is also the simplest. Ask everyone who has the company open to close it, then try again. If you are not sure who is in the file, Sage 50 can show you the users currently logged in, depending on your edition and how your installation is set up.
Once the last person exits, the single-user request should succeed. If it does not, a stale lock is the likely culprit, and restarting the machine that hosts the data file is the next step.
Check for abandoned sessions
A workstation that lost power or lost its network connection can leave a session that never logged off cleanly. Restart that workstation if you can identify it. If you cannot, restarting the server or host machine that stores the company data will usually release the lock.
Do not delete lock files or system tables by hand while guessing at their purpose. That risks real damage to the company data, which is a far bigger problem than the message you are seeing now.
If the lock will not clear
If restarts do not release it, or the message appears when you are certain nobody else is connected, the data may have an underlying fault. Our engineers can examine the file and tell you what is holding the lock. We offer a free evaluation, and you can contact E-Tech about a specific file or read about our Sage 50 database repair service.
If you were trying to open the file single-user to prepare a conversion, our Sage 50 to QuickBooks conversion service handles the extraction for you, so the mode the file opens in becomes our problem rather than yours.