I've opened a file from someone else's project, and saved it as a different file name in order to make an edit to it without disturbing the original (which is in a number of drawings and assemblies).

I replaced a few components before changing the hose to a different size/type whatever. Only now, the tube doesn't show up at all? I can see the route, and the tube exists within the route properties, but nothing changes. What am I doing wrong? The only way I know how to fix this is to find the assembly in which the original was made and start from scratch with replacing the new one.

Where did I go wrong? How do I properly replace a tube?