GATT Error / printer won't connect

If you're trying to print a receipt and you see a popup that says "Printing failed: GATT Error Unknown" or "GATT operation not permitted", the Bluetooth connection to your printer dropped. This is normal — it happens when the printer goes idle or the tablet sleeps. The fix takes about 15 seconds.

Why this happens

Bluetooth devices go to sleep to save power. When the printer wakes up (or when the browser wakes up from screen lock), the connection needs to be re-established. Amari tries to auto-reconnect, but sometimes the browser needs a nudge.

The 15-second fix

Check the printer's power light

Look at the printer. Is the blue light on and blinking? If it's off, the printer shut down — press the power button once to turn it back on.

Tap Reconnect Printer in the error dialog

The error dialog usually has a Reconnect or Try Again button. Tap it. The browser re-pairs with the printer in the background.

If that didn't work — go to Settings → Printer

Tap Settings → Printer in the sidebar, then tap Disconnect followed by Connect Printer. A fresh Bluetooth dialog appears — tap your printer and pair again.

Print a test receipt

Hit Print Test Receipt to confirm the connection works. If the test prints, go back to the POS and reprint the receipt you were trying to print before.

If it still doesn't work

Try these in order:

Turn the printer off and back on — wait 5 seconds between off and on
Reload the browser tab — pull down to refresh on mobile, or press F5 on desktop
Close and reopen Chrome — not just the tab, the whole app
Toggle Bluetooth off and on on the tablet
Check the paper — if the paper roll is empty or jammed, the printer won't respond to commands
Move the tablet closer — Bluetooth range is about 3 meters; walls and microwaves weaken the signal

Safari on iPad does not support Bluetooth

If you're on an iPad using Safari, printing will never work — Safari doesn't support Web Bluetooth. Install Chrome on the iPad, or switch to an Android tablet. Sorry — this is an Apple limitation, not something Amari can fix.

Sales still save even when printing fails

Good news: the sale is already saved in the database the moment you tap Charge. A failed print does not mean the sale was lost. You can reprint the receipt any time from the Sales page once the printer is reconnected.

Setting up your Bluetooth receipt printer
Reprinting a receipt