The setting about adding the Media button to rich editors is misleading

Symptoms

When creating a CRED form, one of the settings offers to include or exclude the Media button to upload and insert fils into the post content editor.

By design, WordPress only allows uploading files to users with specific capabilities, naturally granted to Authors and above. That means that by default, Subscribers and Visitors do not have that capability, hence the button is not displayed either in CRED forms.

Workaround

We do not consider this to be a bug, since the capability to upload files to the server is managed separatedly from CRED. Anyway, the next version of Toolset CRED will include a tooltip behind this setting, explaining that limitation.

In any case, you can always use Toolset Access to grant the upload_files capability to whatever role you want.