How to Resolve Sage 50 "Already Logged In" Error: A Practical Fix Guide That Actually Works
If you use Sage 50 regularly, chances are that you've encountered this warning at a minimum
"Another user is already logged in" or
"Sage 50 is already logged in on this computer"
And the frustrating part? You know that nobody else has at the same time.
The error doesn't typically mean Sage is damaged. It's because Sage believes that that a user's session active, which is usually the result of an improper closure, a network failure or an application running in background that didn't shut down properly.
The good news is that, generally this issue could be fixed without reinstalling Sage or contacting support- in the event that you can pinpoint what's causing it.
Let's dissect it properly.
What Does the "Already Logged In" Error Really Mean?
Sage 50 uses session and lock files to keep track of who's accessing the company's information. If everything shuts down properly those files are removed immediately.
The error is apparent in the following situations:
sage 100 support [here.] closes unexpectedly
The system stops or restarts
The network connectivity is reduced
A user logs off incorrectly
Sage processes still operate in the background
In the simplest terms, Sage believes a user session is open even when it isn't.
Common Situations Where This Error Appears
This error is usually seen in one of these scenarios:
Sage is opening Sage after a power interruption
Users can be switched on and off the shared system
Accessing Sage 50 through a multiuser configuration
Opening the same company's file twice
Logging in after a force Windows update

Remote desktop sessions ending abruptly
Knowing when it happens helps determine how to correct it.
Step 1: Make Sure Sage Is Fully Closed Everywhere
Before you tackle technical fixes do the obvious--but do it right.
Check on the Same Computer
A restart is a way to clear the background processes more often than you'd anticipate.
Check Other Computers (Multi-User Setup)
When Sage runs on several systems:
You can ask other users to log out
Ensure no one has Sage at a minimum or that is idle
Start the server again if you need to.
Some "already logged in" errors originate from closed sessions that were forgotten on a different machine.
Step 2: Stop Step 2: Remove Sage Processes from Task Monitor
Sometimes Sage looks as if she's closed, yet isn't.
How to Do It
Press Ctrl + Shift + Esc
Open Task Manager
Look for:
Peachw.exe
PeachwServer.exe
PeachTree.exe
Choose each and click End Task.
Once done, reopen Sage 50.
This step alone fixes the issue for a huge variety of users.
Step 3: Check and Remove Temporary Lock Files
This is the best fix when the error refuses to disappear.
Sage creates lock-files within the company data folder.