Here is my review of the UX copy for the invalid password error message:
Here's how I would rewrite this error message:
Hmm, that sign-in didn't quite work. To keep your account secure, please try again with a password that: - Is at least 8 characters long - Includes a number or special character
You got this!
This version is more concise, separates out the password requirements visually, and strikes a better balance between friendly and clear. The focus is on enabling the user to move forward confidently.