PAN and ZOOM FUNCTIONS STOPPED WORKING in 2D window

[NSTODELL]

For some unknown reason, I can no longer use the pan or zoom - they don't work if I point and click on the Ui and they do not function with my mouse, nor can I use the spacebar on the key board to drag the 2d model around that pane. It is frozen.

In the 3d window, all the mouse functions work perfectly/as normal (so no it is not the mouse) - I can zoom in and out with the scroll wheel and pan around as usual, its just the 2d window - literally nothing works, whatever tool I select. It is effectively useless.

The panel is not 'locked'(icon top left) and ive restarted the app and the computer - no change.

Any ideas anyone? The program is unusable right now in this state.

Thanks