CASDK-0005: Unable to Request an OAuth Access Token When Testing the Resource Owner Password Credentials Security Policy

This error may occur when testing a connection that uses the Resource Owner Password Credentials security policy. If this error occurs, follow the workaround described below or switch to one of the other supported authentication security policies.

CASDK-0005: A connector specific exception was raised by the application. Cannot request 
OAuth access token.

Workaround: As suggested by Salesforce, add your custom domain URL to the Properties section on the Connections page. Under Optional properties, enter your current My Domain value in the Custom domain field (for example, sfcustomdomain). See Obtain the Custom Domain Name.

Note:

Do not include https:// as a prefix or my.salesforce.com as a suffix.