Are you trying to rotate the pieces? You can't rotate the pieces that come in A, B, C and D options. Those letters represent the different rotations. Have a look at this tutorial - the writer explains it in there. You probably don't need to work through it, but it's worth the read - there are a lot of useful tips, including an explanation of the naming convention.
Hi AndalayBay. Thanks for your reply. I am not trying to rotate the tiles. I glanced through the tutorial (but didn't fully work through it), and based on the naming of the tiles I had expected them to work together. Even at a glance, they look like they should, but unless I'm missing something that doesn't seem to be the case.
Originally I had the editor set to snap to grid in increments of 1. When I ran into this problem, I turned snap to grid off and I tried making tiny adjustments to the X and Y coordinates of the CRmCornerInExitN02C tile to line it up properly with CRmWall02, but still couldn't seem to get it right.