: Internal hardware issues, such as a loose or improperly soldered TF/SD card chip inside the KESS device, can prevent the tool from correctly handling the writing buffer. Recommended Solutions Update Windows Components Microsoft Visual C++ Redistributable
At 98%, the buffer held.
Are you using a genuine Alientech tool or a clone, and which specific ECU model are you attempting to write to? checksum buffer error : General tuning | ecuedit.com
This error essentially means the software has detected a mathematical mismatch between the data in the file and what the ECU expects. If ignored or bypassed incorrectly, you risk "bricking" the ECU, rendering the vehicle unstartable.