I tried to edit the source text using the Edit segment menu.
I first unlock the source segment, edited the text, and click Save and got an error message briefly showed up.
Two problems:
1) I could not read the error message first because the View/edit segment window hides part of the error message and the message was displayed only for a few seconds. I could read the error message after changing the view%.
2) The error message says "Set all mandatory custom fields before saving the segment." I do not want to display any custom fields associated with the segment. All I want to do is edit the Japanese source text. Could you please help me with this?