Create a category in the menu. In the admin panel there appeared a black diamond with a question mark. The site does not appear subcategory. How to get rid of this problem?
Doing a search, I found the black diamond problem discussed in this thread. Perhaps it will help you?
Sadly, my only idea is within that thread, specifically this post. I know how frustrating it is as I also spent many hours troubleshooting. It has something to do with html_entity_decode. Once you find the potential html_entity_decode statement causing the problem and remove it, you may also have to go back to any existing data and reformat it (as mentioned here). Sorry I can't be of more help.
I can see the way: i found by searching "html_entity_decode" in files hotaru, then remove decode in the all line, in turn.
