Unable to upload any file with File component

[jiaweichong]

Describe the bug
Unable to upload any file with File component

Version/Branch
Latest version, https://formio.github.io/formio.js/app/builder.html

To Reproduce
Steps to reproduce the behavior:

1. Add a File Component with Form Builder on https://formio.github.io/formio.js/app/builder.html
2. Set Base64 as storage, leave everything else as default
3. Upload a file on the component here
   
4. The error below is shown
   

Expected behavior
The file (document or image) can be uploaded successfully and able to see the preview

Screenshots

Additional context
Add any other context about the problem here.

[vassilidev]

some news ?

[daneformio]

This component does not work in the sandbox. Certain components are open source, and you can use them as front end components and build out the server side functions. Else, we provide server side functionality for easy integration in our commercial platform, which thousands of customers around the world choose to purchase in order to access the enterprise feature functionality.

[vassilidev]

I want to use it with url provider, i cant make it work, only webcam image work (binary in post request)