WARNING - AliExpress blocks most URLs in Messages

Use the AliExpress app or the website, then hover over your account's icon -> Message Center.

A message at the right will be displayed in the Messages floating banner: "Start chatting now!".

If you try to send some URL to any contact or store, most of them will be blocked. I don't understand this reason, but it's likely due to the Chinese government not wanting any of its citizens to access content outside the approved walled warden. This is unreasonable, since makes it much more difficult to explain issues or ask for questions, and you have to circumvent it by disassembling the URL into pieces so are not recognized as such.

Messages from AliExpress' Message Center watch out for "external" URLs

The warning is as follows:

Note: This message contains prohibited content and hasn't been sent. Any further messages of this nature may result in account restrictions.

AliExpress still has a long way to go, to be as good and pleasant to use as other digital marketplaces, like Amazon.