Let me give you more details about what I did.
1. X-plane was running fine with SMP and Simple Seasons (by ShePooley), along with two other plugins (xgs and detaref editor) in my old computer. I built a new computer and then copy-pasted the entire x-plane 10 folder from old desktop to new desktop. In the process I was warned that the symblink(? or symlink?) could not be copied.
2. On the new computer, I deleted all preference files. X-plane could start and run. Then I saw the yellow msg. Thinking copy-paste may have messed up with license issue, I did an uninstall and reinstall of SMP. After that the x-plane won't start anymore. It simply sent a crash report.
I am really at a loss as to what is the cause. Looking at the log file seems to point the finger at Gizmo, especially it restarted 5 times. Does x-plane automatically shut down after x times of restarting some plugin?
Thanks for your explanation. LOL, I know the word "error" to a layperson like me could be very different from the definition used by a computer expert. No worries.