Thank you for reaching out to the Community! I apologize you're having this experience with your email. I took a peek at your most recent campaign and was unable to replicate your text moving or this same error message. I was however able to see why your text is changing colors. The global body font in your email is currently set to white.
Changing this global font color to black will stop the text from turning white. What are some of the other formatting movements are you seeing in your email? What steps did you take before seeing these changes in your text or this error message? Have you tried working in a different browser or a private/incognito window? Once we have these details we can troubleshoot this further for you.