The app won't sync after reconnecting

Your handheld shows Wi-Fi again, but the pending-sync count is not dropping and new scans are not appearing in reports. This is almost always a connection or session issue rather than lost data — offline scans stay safely on the device until they upload. Work through the causes below in order.

Likely causes

• Captive-portal Wi-Fi. Guest or shared networks show "connected" but silently block traffic until you accept a login page.
• Expired session. The login timed out while the device was offline, or an app-pool recycle on the server logged everyone out, so the upload is rejected as unauthenticated.
• Server not reachable. On on-premise installs the device is on a network segment that cannot see the warehouse server; on cloud, the internet link is down.
• A conflicting transaction. One queued scan clashes with a change made by another operator and stalls the queue.
• Wrong clock or address. A badly wrong device date/time or an out-of-date server address can break the connection handshake.

Step-by-step fixes

1. Open any normal web page in the device browser. If a Wi-Fi sign-in screen appears, complete it — that clears a captive portal.
2. Log out of Fast WMS and log back in to refresh the session, then trigger the sync again.
3. Confirm the device can reach the server: load the Fast WMS login page. If it will not load, the problem is the network, not the app.
4. Check the pending count. If most transactions clear and one sticks, open it — it is likely a rejected scan or a conflict; correct or discard just that item.
5. Check the device date and time are correct and set to auto.
6. If it still won't upload, do not clear app data. Note the pending count and contact support so we can recover the queue.

To reduce how often this happens, learn how offline scan mode buffers work and sync frequently. If the real issue is that no one can even sign in, see Can't log in to your account.