A puzzle is rejected#
Check for duplicate givens in each row, column, and 3×3 box. A puzzle with no valid solution cannot be started. A puzzle with multiple solutions may be accepted as a beta case, but exact mistake checks and hints are limited.
A camera scan is inaccurate#
Retake the image with the entire grid visible, even lighting, minimal glare, and little perspective distortion. Review every recognised given before saving. The Camera import guide covers permissions and image preparation.
The camera does not open#
Camera import uses Google Play services’ document scanner. Check that Google Play services is available and current, then confirm that camera access is permitted. Regular puzzles and manual entry remain available without camera access.
Progress or statistics look wrong#
Confirm that you resumed the intended saved puzzle and that the selected difficulty and period filters are correct. Deleting saved progress removes its moves and checkpoints; deleting an imported puzzle removes it from My Puzzles.
Before reinstalling or clearing app storage, assume locally stored progress may be lost unless you have verified a current transfer or backup option.
A Daily Challenge is unavailable#
Check the device date, time zone, and network connection. Available difficulties and comparison options can depend on Premium status. Restart the app after correcting device time or connectivity.
Premium is not recognised#
Use the Google Play account that made the purchase, connect to the internet, then open Settings → Premium → Restore Purchases. If it still fails, restart Google Play and Lab Sudoku and verify that the purchase appears in the Play account’s order history.
The board is hard to read or control#
Try another colour theme, number font, grid style, candidate layout, number-pad layout, or board position. Reduce animations where motion is distracting. See Customising the board and the Accessibility statement.
Still need help?#
Use the Support page and include the app version, Android version, device model, and exact reproduction steps. Redact unrelated personal information from screenshots.