Cannot create order or accept payments

From two days ago we are unable to create new orders from the admin panel (if you click change guest or add item, then nothing happens). Users can also not complete payments on the site, and installed widgets is not working either. I have already gone through the process of deactivating all plugins to see if there is not perhaps a clash, but doing this did not correct the order creation issue. And payment method and widgets is also still not working. I made sure that Eduma, LearnPress and ThimPress are all the latest versions, so guess it might be on your side. Please help!