[2021] Arena won't let me play my new Deck

Soo as the title says, I built a new brawl deck yesterday with Esika as a Commander and Obosh the prey piercer as a companion. Honestly, I just built it for fun and didn't even know if it would work. After I finished, I was eager to try it out but no matter how many times I tried or how long I waited, Arena just loaded and did not stop. Anybody maybe got an idea whats wrong? Maybe I overlooked something, I'm relatively new to playing Magic, so sorry if this is a stupid question