Appeal deadline questions after an unemployment denial after 10 years as a teaching assistant

My claim was denied after 17 weeks of waiting, and the letter says I have a short window to appeal. I do not usually post, so bear with me. My employer's version of events does not match mine, and I have emails that show it. Did you bring documents or only talk?

Thanks for writing this out. I went through something close to it 14 months ago, and it settled down once I kept a simple log of every call and form.