Wrong-label protection and alert emails
How Laberty stops a job before it prints on the wrong labels, why some printers can't be checked, and who gets emailed.
Printing a stack of jobs on the wrong labels wastes a roll and a morning. Laberty checks in two places, and tells the people who can fix it. This is part of Home and Business.
Check 1: Laberty's record
Laberty keeps a record of what's loaded in each printer, on Admin → Printers & stock. When an app sends a print job through the API and says which labels it's for (the stock field), Laberty compares the two before doing anything else:
- Different labels recorded: the job is refused with
409 stock_mismatch. Nothing is rendered or queued. The response says what's loaded and what was asked for. - Nothing recorded: the job is refused with
409 stock_unknown. - Your admins get an email such as "Load Large Address (208) in Kitchen QL-820NWB". It's sent at most once per printer and label every half hour.
This check is only as good as the record. It can't see a roll someone swapped by hand.
Check 2: the printer's own report
Just before printing on a Brother QL by IP, the bridge asks the printer what is physically loaded. This applies to every job the bridge prints on that printer. If the printer answers:
| The printer reports | The job | The email says |
|---|---|---|
| Different labels from the job's | Stops with stock_mismatch | Wrong labels loaded in printer |
| No labels | Stops with no_media | printer is out of labels |
| An error, such as the cover open | Stops with printer_error | printer needs attention |
Nothing is printed. Fix the problem, then print the job again.
Some printers don't answer
Not every printer replies over the network. A QL-820NWB tested over the network accepted the connection but sent no status reply.
When a printer stays silent, the bridge prints without checking and writes did not report what is loaded; printing without checking in its log. For that printer, Laberty's record (check 1) is the only protection. So:
- Press Swap roll on the printer's card every time you change the roll.
- If several people or apps share the printer, agree who updates it.
Other problems that email your admins
| Code | The email says | What to do |
|---|---|---|
unreachable | Laberty can't reach printer | Is it on? Is it on the bridge's network? Did its IP address change? |
no_address | printer needs its IP address | Add the address on Printers & stock |
Who gets the emails
- Every admin in your account who has an email address on Admin → Users. Members aren't emailed.
- They come from
alerts@laberty.app. Add it to your contacts so they don't land in spam. - Each email has a button that opens Printers & stock.
- One email per printer per problem per half hour, however many jobs are waiting behind it.
Each problem is also recorded in your account's activity log.
What isn't checked
- Printing from an iPhone or iPad. The Share menu sends the labels straight from the device to the printer, so Laberty can't see the roll. The print screen shows the label size it will use, with an actual-size preview. Check it matches the roll.
- Receipt and ZPL printers. They're not checked for label type.
- Printers that don't answer the status question, as described above.
Still stuck?
Contact support and tell us what you tried. We reply by email, usually within 1–2 business days.