Hi @Mike_Moritz, welcome to the Asana Community Forum! sorry for the trouble here.
This type of error are usually related to the amount of characters you have in the task description, usually if it’s close to the limit of 65k characters. If there is too much information in the subtask description or you are attempting to copy and paste a very large amount of characters into the description, for this reason you’re receiving this error.
As a workaround, you can create another task or subtask to add additional content or you can add more details in a comment.
If your subtask description doesn’t have close to 65k characters, I recommend you to contact our support team and please share the subtask URL and the URL of this thread so they can investigate this further.
I hope this helps! Let me know if you have any questions 