Hello everyone,
Due to the
recent update of policy of Customer Match, your request for mutating CrmBasedUserList will fail if the advertiser account hasn't been whitelisted for using the feature.
If you own the account, you can contact your Google account representative to get your account whitelisted.
If the account belongs to your customers, they need to contact their Google representative for whitelisting.
Best,
Thanet, AdWords API Team