Printer Issues
Help with printers that do not appear, labels that print in the wrong size, and barcodes that will not scan.
This page covers printing from the application. If you generate labels through the REST API and need help decoding the returned PDF, see API Issues instead.
The Label Print App prints directly to printers installed on the computer, configured under Settings → Print → Labels. Online Label Print produces a PDF that you download and print from your browser's own print dialog — most of this page therefore applies to the installed application.
My printer is not in the list
Open Settings → Print → Labels and check the Printer list.
The application re-reads the Windows printer list each time the printer settings are opened. A printer you install, rename or remove while the application is running shows up as soon as you close and reopen the printer settings — you do not need to restart the application.
This applies from version 3.4.3 onwards (release notes). Earlier versions kept the list until the application was restarted. Your version is shown under Settings → Version information.
So if a printer is missing, the reason is almost always that Windows itself does not offer it to the application. Work through the checks below.
The printer must be installed and connected
Open Windows Settings → Bluetooth & devices → Printers & scanners and confirm the printer is listed there first. If it is not in this list, the application cannot see it either.
Check the status shown under the printer name:
- A printer marked Offline is installed but not reachable — switch it on, check the USB cable, or check the network connection for a network printer
- A printer that has just been switched on can take a few seconds to change from Offline; reopen the printer settings in Label Print afterwards
- If the printer is missing entirely, install it with Add device and the manufacturer's driver
The application runs as a Windows service
A Windows service only sees printers installed for the account the service runs under. A network printer you added under your own Windows profile does not exist for the service, so it never appears in the list — even though it prints perfectly from Notepad.
Have the printer installed for the service account, or use a network label printer addressed directly by IP (see below), which does not depend on Windows printer installation at all.
"Failed to refresh list of printers for label printing"
The application could not read the printer list from Windows. Confirm the Windows print spooler is running (Services → Print Spooler), then reopen the printer settings.
The list still does not update
Check your version first, under Settings → Version information. On anything older than 3.4.3 this is expected — the list is kept until the application restarts, and updating the application is the real fix.
On 3.4.3 or later: if Windows lists the printer but Label Print does not, even after closing and reopening the printer settings, restart the application — that always rebuilds the list. If you find you need a restart every time a printer changes, report it: the automatic refresh is not working on that installation and should be fixed rather than worked around.
Nothing happens when I print
1. Check the printer type
Open the printer entry under Settings → Print → Labels and look at Printer type. If it is set to PDF - Save to local folder, no printing takes place at all — the label is written as a PDF into the folder configured in Path to folder where PDF file will be saved. Check that folder before assuming the print failed.
2. Check the printer is enabled and default
- Status on the printer entry must be enabled
- If several printers are configured, one must be marked with Set as default printer
- If the printer is restricted under Users, your user must be in that list
3. Print a Windows test page
This is the quickest way to decide whether the fault is in Label Print or in Windows. Open Windows Settings → Bluetooth & devices → Printers & scanners, select the printer, and choose Print test page.
| Result | What it means |
|---|---|
| The test page does not print | The problem is the printer, its driver or its connection — not Label Print. Note the Printer status shown at the top of this screen. |
| The test page does print | Windows can reach the printer, so the fault is in the Label Print configuration — go back through steps 1 and 2 above, and check the settings under The label prints in the wrong size |
While you are on this screen, open Open print queue as well. Jobs stuck in the queue block everything sent after them — cancel them, and if the queue will not clear, restart the Windows print spooler.
Network label printer: "Failed to send ZPL via socket to …"
Thermal printers addressed directly by IP receive the label over the network, normally on port 9100. The application waits about five seconds for the printer to answer before reporting this error.
Check, in order:
- The printer is switched on and ready — not asleep, not in an error state, and not out of labels
- The IP address is still correct. Printers that get their address automatically can change it after a restart. Give label printers a fixed address.
- The network path is open — the printer answers on port
9100, and no firewall between the computer and the printer blocks it - The printer is on the same network as the computer running the application, or is reachable across the VPN
Check the Windows print log
When a job leaves Label Print without error but nothing comes out of the printer, Windows itself records what happened to it. This log shows what neither the application nor the printer will tell you.
- Press Windows + R, type
eventvwr.mscand press Enter - In the tree on the left, open Applications and Services Logs → Microsoft → Windows → PrintService
- Right-click the Operational log and choose Enable Log if it is not already enabled — it is switched off by default, so you may need to enable it and then reproduce the problem once
- Print again from Label Print, then refresh the log and read the newest entries
What to look for:
| Entry | Meaning |
|---|---|
| A job printed successfully with the right document name | Windows accepted and spooled the job — the fault is at the printer or its driver |
| A job deleted or failed to print | The spooler dropped the job, usually a driver or permission problem |
| No entry at all for your print attempt | The job never reached Windows. For a network label printer this is expected — those are sent straight to the printer and bypass the Windows spooler entirely. Otherwise, check the printer type and settings in Label Print. |
This log is also the right thing to attach when reporting a printing problem to support.
The label prints in the wrong size
All of the following live on the printer entry under Settings → Print → Labels.
| Setting | What to check |
|---|---|
| Paper size for labels printing | A6 for thermal label printers, A4 for office paper |
| Printer media size | Automatic (detect loaded roll) follows the roll actually loaded in the printer. If the detection is wrong, choose Paper size default and set the paper size explicitly. |
| Scaling | Use Actual Size for labels. Shrink to Fit, Stretch to Fit and Scale to Fit resize the label and are the usual cause of labels that are too small, stretched, or cut off. |
| Paper tray | Must match the tray the label stock is actually in |
Also check the paper size configured in the Windows printer driver — if the driver is set to A4 while the printer holds A6 labels, Windows scales the label down before it reaches the printer.
The barcode will not scan
Almost always this is a scaling or resolution problem rather than a damaged label.
- Set Scaling to Actual Size. Any other setting resizes the barcode, and a resized barcode loses the sharp edges scanners need.
- Match the printer resolution — set the printer driver to 203 dpi or 300 dpi according to your printer's manual, and do not mix a 300 dpi driver setting with a 203 dpi printer.
- Do not print a label that was scaled once already — for example, a PDF printed with "Fit to page" in a PDF viewer.
- Check the print head and labels — streaks, faded areas or a dirty print head break the bars. Clean the head and replace the roll.
- Check the darkness/contrast setting on the thermal printer if the print looks grey rather than black.
The label is printed in the wrong position on an A4 sheet
When printing labels onto A4 sheets, the position is controlled by:
- Paper print start position — Upper left, Upper right, Bottom left, Bottom right
- Remember last print position — continues on the next free position instead of always starting at the first
- Show label dialog when position is not remembered — asks for the position at print time
For small, consistent misalignment on every label, correct it with Left offset (mm) and Top offset (mm) rather than by changing the scaling.