Shipping Errors: NO WARNINGS: What is going on?

Also found in this thread: https://www.pathofexile.com/forum/view-thread/3535831

Shipping gets arbitrarily cancelled or will not run, with the whole UI just resetting and not telling you what the problem is.

Not a single tutorial or in-game notice telling us what the issues are.

HAS to be a bug, or something major is missing from the UI.

This is absolutely infuriating