Updated to the newest RC1 version and went to read a P12 and had a hard time reading through V8 (3 attempts one was a $101 error, another was a $0311 with a $11 Mode Not Supported) it finally read all the way through but gives a error that the calibration contains one or more invalid/incorrect checksums, OS has red "X" beside it says OS is 12627882, checksum is $6FDDC631.

Says in error block balloon, will not let me reflash due to checksum error.

It use to work fine what happened? Old checksum in an older tune is $D14F1F23, seems "engine operation" and OS are different, old "engine operation" checksum $2E10FFAA, new checksum $A5570DD4, when I say old it is still a .ctz file.

I just did "update checksum' and got a warning message that it could corrupt the controller, safe?
Has green check mark now.