I downloaded the Mod and it worked for about an hour. Then next time I started up, and since then, I can place the modified underground belts and use 'Ctrl B' to place belts under the ground, but items won't transfer from above ground belts to the underground system. Items appear to stop at the modified underground belt - no error message or other indication of what is wrong.

Can't reproduce this. In my testing the connectors continue to work after a save and load. Can you post the broken saved game?

Sure, thanks for responding. I've set up a tiny Beltlayer belt to show you what is happening. I've found the saved file, but I am not sure how to 'upload' it so you can see it, can you explain?

If it's easier, post a message on the forum thread and put your saved game as an attachment. Are you sure you've rotated the connector the right way around, using the R key, the same as regular underground belts?

Yes, I even tried to rotate it incorrectly, just to make sure I had it right, but that wasn't the problem. I'll try to save the game. The Mod isn't working on several games I've tried, so it may be something I've set up incorrectly at game level rather than within each individual game. I've posted a message on the Forum with the file attached. Thanks.

It possibly a conflict with another mod and it’s easiest if you can post a saved game so I look at the situation closely.

Hi therax, I did upload a saved game onto the Forum. Let me know if you can't access it there. Its on the Beltlayer Mod page: https://forums.factorio.com/viewtopic.php?f=190&t=62567&p=389218#p389218