i use chrome to connect with mindjet.com, and create many mind maps, I think it's a easy way to work on different devices. But, today I want to continue edit one of my mind maps, while I was opening the mind map using chrome as usual, I found all the subtopics can not extend, and this mind map shows "read only". I checked other of my mind maps and can not reproduce this issue. please help me to fix this bug. Thanks.