Hai yangchunlong,
Que #1: why this error dialog window?
Ans #1: Your metadata file corrupted. It happen by more reason I personally faced by improper closing of software.
Que #2: where could I find out the log file?
Ans #2: In your S32DS workspace "..\workspaceS32DS.3.4\.metadata\.log"
Thanks
Kalaimani Arumugam