When you look at the properties for the pdfViewer you will see that there is a 'Connector' property under the 'PDF' Category. This does not set a value by default but you can choose to set the pdfConnector found in you global container (image attached for reference)
If you have not done this, set the value to your pdfConnector and try again. Please let me know what your results are.
Please open a Support Request, as this issue will need to be investigated in more detail. If you do not have access to the Support Portal, contact your Support Portal Administrator so that a Support Request can be opened on your behalf.