The plugins is not able to retrieve changesets from branches contains "/" on their branch name from Bitbucket.
Examples:
Retrieving feature/ChangeRequests ... failed (Resource not found).
Retrieving feature/DescriptiveNames ... failed (Resource not found).
Retrieving feature/initial_commit ... failed (Resource not found).

Problem:

if( !preg_match( '/*|^[a-zA-Z0-9_., -]*$/', $f_master_branch ) ) {
echo 'Invalid parameter: 'Primary Branch'';
trigger_error( ERROR_GENERIC, ERROR );
}
From SourceBitBucket.php is not allow to have "/" in the branch name