Act as a senior UX writer. My product is product and what it does, my audience is audience and the brand tone is formal, friendly, technical, playful. Write the microcopy for the situations I list here: list the screens, errors or states. For each one, deliver: 1) A headline of 6 words or fewer. 2) Supporting text of 2 sentences max, explaining what happened and what the person can do next. 3) The primary button label, always with an action verb, never just "OK". 4) A shorter alternative version for mobile screens. Follow these rules. Never blame the user and never use the word "invalid" on its own, always say what to fix. Avoid technical jargon and error codes in visible text. For empty states, point to the next step instead of only saying there is nothing there. Keep the same grammatical person across all copy. Present everything in a table with the columns Situation, Headline, Supporting text, Button and Short version.