When I click 'ship' for an order the page reloads with just some form HTML with no head or scripts.
Testing so far hasn't shown any issues with other functions on the page. We can invoice, hold etc.
This is an old order (using for testing) but it replicates on all orders, even current ones. All orders tested have had different shipping methods.
Has anybody come across this before? Searching around is giving me absolutely nothing!
All plugins are up to date.