Troubleshooting
What goes wrong with Product Barcode & Label Printing, how to recognise it, and what to do.
Nothing happens when I press Print
Odoo produced no PDF, which almost always means wkhtmltopdf.
- Settings - Technical - Reporting - Paper Formats should exist. If the Reporting section is missing, developer mode is off.
- Try printing any other Odoo report - an invoice, a delivery note. If that fails too, the problem is wkhtmltopdf and not this module.
- Check the server log for wkhtmltopdf messages when you press Print.
Odoo recommends wkhtmltopdf 0.12.6 patched with Qt. Older builds ignore page sizes, which is exactly the kind of thing a label module notices first.
Every label is out by the same small amount
The print dialog is scaling. Set Scale: 100%, not "Fit to page". Fit-to-page shrinks by about 4%, which is 8 mm across an A4 sheet.
Print a test sheet, measure the total width of the printed grid, and compare it with what the template says it should be. If it is short by a few percent, that confirms it.
The first row is right, the last row is wrong
Vertical drift. The vertical gap is slightly off and the error accumulates downwards. Adjust the gap, not the top margin - correcting a gap error with a margin makes the top wrong instead.
Measure across the whole sheet and divide, rather than measuring one row: it divides your measuring error by the number of rows instead of multiplying it.
The first column is right, the last column is wrong
Same, horizontally. Adjust the horizontal gap.
"... do not fit on a 210 x 297 mm page"
The columns, rows, margins and gaps add up to more than the paper. Reduce something. The commonest cause is entering a label width as a margin.
The content is cut off on the label
There is no font size at which four lines fit on a 21 mm label. Turn something off in the template, or reduce the font sizes, or use bigger labels.
Content is clipped rather than pushed onto the next label - that is deliberate, since overflowing into the neighbouring label would ruin two.
The barcode is blank on every label
The barcode type is forced to EAN-13 and the product's barcode is not a valid EAN-13. Set the type back to Automatic, which uses Code 128 for anything that is not genuinely thirteen valid digits.
The barcode will not scan
- Height. Give it 8-10 mm. Under about 6 mm, hand scanners struggle.
- Quiet zone. A barcode filling the whole label width has no white space either side. Make the label wider or the barcode area narrower.
- Print quality. A draft-mode or low-toner print produces bars that bleed together. Print at normal quality.
- Size. On very small labels, switch to QR - it stays scannable where a linear barcode does not.
One product prints "No barcode"
It has no barcode. Set one on the product, or turn the barcode off in the template.
A roll printer feeds a blank label between prints
That is the printer's media or gap setting, not the PDF. Odoo produces one page per label at exactly the label size; what the printer does between pages is its own configuration.
Roll labels print on a full A4 page
The print dialog is using its own default paper size. Choose the label size in the printer settings, or "use printer's own", and turn scaling off.
The wizard opens with no products
You opened it from Labels - Print Labels rather than from a product list. Add products by hand, or close it, tick products in a list, and use Actions - Print Labels.
"You are not allowed to modify Product Label Template"
Changing a layout needs the Label Designer group, because it changes the output for everyone. Settings - Users & Companies - Users - (user).
"That is N labels. The limit is 5000"
A quantity is wrong, or the job genuinely is that big. Check the lines; split the run if it really is.
Still stuck
Email info@technovision.dev with your Odoo version, the module version, a screenshot of the template form, and the printed test sheet if the problem is alignment. The template's numbers plus the printed result is usually enough to diagnose it immediately.