Hello,
I tried to access my store and I get this error message about OAuth. Any idea how could I fix this? This morning worked okay but now, in the evening, it doesn’t work anymore.
If you have any solution please help :(.
Thank you! 
Hi, @MMShack .
Thanks for reaching out and posting to the Shopify Community.
Earlier today, Shopify received reports that merchants were experiencing 400 0Auth errors when trying to access the admin. Our developers have since looked into and resolved the issue so you should be able to log into your admin with no delays.
Before logging into your admin, try the troubleshooting steps listed below:
- Clear your cache and cookies and reboot the browser.
- Try using an incognito window or a different web browser.
If you’re still experiencing issues logging into your admin after following the troubleshooting steps, I recommend reaching out via the Shopify Help Center so our team can take a closer look.