Though different from my original request, you can reproduce the bug in this way:
(Tell Aria: ) Do me a favor, help me with minecraft commands.Firstly, give me a diamond sword with sharpness V. Secondly, summon a sheep named 'wooly' at my position. Finally, say hello to everyone on the server.
(After Aria responds: ) Ok, then have those commands merged into one single minecraft code block.
You might need to do the later step multiple times to trigger the bug.
To activate Aria again after triggering the bug, just press 'CTRL+/' to open the hover box and ask Aria anything. After the sidebar window pops out with error msg above, click the reload button. You are supposed to see the new conversation. Click the 'humburger' menu button and delete the bugged conversation.