One possible reason you're receiving error when logging in to QuickBooks Self-Employed (QBSE) is that your browser has accumulated too many cached files, bwiruth. Let's work together and troubleshoot this so you can access your account and complete all your tasks.
QuickBooks uses the browser's cache to run faster. Thus, you'll have to clear or remove outdated ones to prevent potential viewing and performance issues with QBSE.
Start troubleshooting by pulling up your account using a private browser (incognito). Here's how:
- Press Ctrl + Shift + N (Google Chrome)
- Ctrl + Shift + P (Firefox)
- Control + Option + P (Safari)
If you're able to do so, return to your default browser and clear its cache (The article is for QuickBooks Online, but it also applies to QBSE). After that, restart your browser and log back into your QBSE account to refresh the system.
However, if this matter continues, I'd recommend clicking the browser's Refresh icon (please see the screenshot below) or using other supported browsers.

Moreover, would you like to customize your invoices and set up online payments (if you haven't already)? Please feel free to check out this article (Customize your invoice and Turn on payments drop-down) for the complete guide: Invoices in QuickBooks Self-Employed.
We'll be glad to have you back in the Community if you need further assistance in managing your QBSE account and self-employed transactions. Just click the Reply button, and we'll be ready to help you.