Almost everything that goes wrong with this app goes wrong at one of ten points, in a fairly predictable order: download, install, first launch, sign-in. Go through them in that order instead of jumping to whichever fix you saw first. Most people find the cause inside two minutes.
Before anything else: identify which stage failed. A download that stops is a network or storage issue. An install that fails is a package or device issue. A sign-in that fails is an account or connection issue. Fixing the wrong stage is the main reason people go in circles.
Download stage
1. The download stalls or stops partway
Nearly always caused by switching networks mid-transfer, a battery or data saver pausing background downloads, or storage running out as the file grows. Cancel the partial download rather than leaving it, stay on one network, disable data saver for the duration, and start again. Do not try to install a file whose download was interrupted. It will fail at the install step with a message that tells you nothing useful.
2. The browser blocks the file
Some browsers hold back non-store packages by default and show a warning instead of finishing the transfer. If you are downloading from a page you trust, choose to keep the file when prompted. If a warning specifically says the file is harmful or has been altered, stop there. That one is not meant to be overridden.
3. The file will not open from the notification
Open your Downloads folder in the Files app and tap it from there. Notification entries sometimes lose their reference after a browser restart, which looks like a broken file but is not.
Install stage
4. "App not installed"
This is a catch-all message, not a diagnosis. Check in this order: did the download complete at a sensible size, is there enough free storage with room to spare for unpacking, is your Android version 5.0 or newer, and is a conflicting version already installed. Restart the phone and try the same trusted file once more before changing anything else.
5. "There was a problem parsing the package"
A parse error means Android could not read the file properly. That points to a corrupted or partial download, or a package built for a newer Android version than your device runs. Delete the file and download it again from the same page you used before. Do not go hunting for a different mirror. That is how people end up with modified builds.
6. Android will not allow the install
Android needs permission to let your browser install apps. Grant it to that browser specifically rather than enabling anything system-wide, complete the install, then switch the permission back off. Steps are in the download guide.
7. The update is refused
Installing a new build over an old one fails when the signatures do not match, which usually means the two files came from different places. Note your account details, uninstall the old version, and install the new package cleanly. This is exactly why sticking to one download source matters.
Launch and login stage
8. The app opens to a blank screen or crashes immediately
Force-close it and reopen once. If it persists, restart the phone, confirm you have a working connection, and make sure the phone is not critically low on free storage. If it still crashes, reinstall the current package from your trusted source rather than trying older versions.
9. The OTP does not arrive
Confirm the number and country code first, then check whether ordinary SMS is reaching the phone at all. Send yourself something from another number. If nothing arrives from anyone, it is the network or a blocked-sender setting, not the app. Check spam or blocked-message folders, then wait for the current code to expire before requesting another. Multiple rapid requests typically make the wait longer, not shorter.
10. Credentials rejected, or the account is locked
Check for a stray space, an autofilled password from a previous account, or caps lock. If sign-in still fails, use the recovery option on the app's own screen. Do not create a second account to get around it, because two accounts on one number makes any later support request harder. Repeated failures trigger a protective lock: stop attempting, wait out the stated period, then use recovery. Continuing to guess extends the block.
Never share an OTP or password with anyone offering to "fix" your account, on any channel. Genuine support never needs them. Account problems go through in-app support only. We cannot reach accounts from this website.
Quick reference
| Symptom | Most likely cause | First fix |
|---|---|---|
| Download stalls | Network switch or data saver | Cancel, stay on one network, retry |
| App not installed | Partial file or low storage | Re-download, free up space |
| Parse error | Corrupted or incompatible package | Delete and re-download from the same source |
| Install blocked | Browser lacks install permission | Allow for that browser, then revoke |
| Update refused | Signature mismatch | Uninstall old build, install cleanly |
| Blank screen | Connection or storage | Restart phone, check connection |
| No OTP | Number, network or block setting | Verify number, wait for expiry, retry once |
| Login rejected | Autofill or typo | Type manually, then use recovery |
| Account locked | Too many attempts | Stop, wait, use recovery |
When to stop troubleshooting
If you have worked through the relevant stage twice with no change, stop and use in-app support rather than experimenting further. Quote the exact wording of the message and the step it appears at. Never include your password or OTP in it. Beyond that point, extra reinstalls and repeated sign-in attempts tend to create new problems rather than solve the original one.
For the flows themselves, see the download guide and the Y1 login guide. For file-source and account-security practices, read the safety guide.