Some users in the HP Tuners forum have found a workaround:
When you originally "Read" the ECU to pull the stock file, there was a communication glitch (dirty voltage, a momentary laptop freeze). The file saved to your computer has a corrupted checksum built right into it. Garbage in = garbage out. hp tuners validate checksum failed
When you see "Validate Checksum Failed," it means the math didn't add up. The data currently inside your ECU does not match the reference number stored in the ECU. Some users in the HP Tuners forum have