Mr.Ken
I cannot judge whether these error is bug or not. And. The problem doesn't resolve essentially.Because, It was unstable to add LTI tool.(My check was not enough...sorry.)
But, I report Moodle Tracker these phenomenon. Because, honestly speaking, I think that my skill and knowledge about moodle is not enough to resolve the problem. I can only report that There is the problem.
But, at least, I could add LTI tool. This is the fact. I cannot thank you enough for this.
Thank you!
masayuki asano