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Fexl Lite

Troubleshooting

Something is broken and you need it fixed before the next customer walks in. This page is a triage map — pick the closest symptom, jump to the page that handles it, work the steps in order. Each sub-page leads with the most likely cause and ends with the “still stuck?” path.

Updated 4 May 2026·For v2.2.0·2 min read

What’s broken right now?

DESKTOP APP

App can't reach its server

“Server is starting…” splash never goes away. Port 8089 conflict, firewall blocking the embedded Go server, or antivirus quarantined the sidecar binary.

 LOGIN

Can't log in / forgotten PIN

PIN doesn’t work, too-many-attempts lockout, the screen auto-locked mid-shift. Owner-recovery and the snapshot-restore last resort.

 CLOUD SYNC

Sync stalled or diverged

Last-synced timestamp hasn’t moved, two devices show different totals, FK resolver complaining in the log. The force-re-pull workflow.

 LICENSE

License invalid / expired

“License invalid” toast at startup. Activation refused on a new device. Offline grace period running out. Where the device-keys file lives.

 PRINTING

Receipt won't print

Nothing happens on Print, garbled characters, blank paper, cut doesn’t fire, network printer disappeared. The most-googled support page on this wiki.

Quick decision tree

Use this when you’re not sure which page to open:

  • You can’t even get into the app. The startup splash hangs, or the login screen loads but rejects every PIN. → start with Connection issues (if the splash hangs) or Login & PIN (if the login form rejects you).
  • You’re in the app, but something is wrong with what you see. Numbers disagree between two devices, an invoice is missing, a report total looks off. → Sync issues.
  • You’re in the app, ringing sales, but the receipt is blank / garbled / not cutting. → Printing issues.
  • A “License invalid” or “License expired” banner showed up. → License issues.

Before you call support

These three pieces of information cover 80% of support tickets — grab them before you open a chat:

  1. Version — Settings → System → About. Looks like v1.6.100. Older builds are missing fixes that may be the cause; the first thing support will ask is whether you’re on the latest.
  2. Platform — desktop app (Tauri) or web. Many features (USB printers, payment terminal, sync worker) are desktop-only.
  3. Recent log lines — the last 50 lines of the server stderr log. Path varies by OS:
    • macOS — ~/Library/Application Support/com.minib2c.pos/server-stderr.log
    • Windows — %APPDATA%\com.minib2c.pos\server-stderr.log
    • Linux — ~/.local/share/com.minib2c.pos/server-stderr.log