@StepInFetchit-Icadar It's odd that resetting the layout to standard layout isn't working.
Can you move the other parts of the GUI a little bit around to be able to grab the Media Pool and move it back to it's original location under the transport control?
I suspect the blank pane to the right is the Control Tab as the Media Pool Folder tab is partially showing under the blank pane and which is by default normally under the transport controls as shown in the image below.
Try pressing F3 to change the state of the pane, if the Tabs do not reappear check the all the View options
If the above fail try resetting the program back to its default settings - File, Settings, Reset...... - note any customisations you have made will be reset.