Adapt-a-roll problem

Last fall I picked up an Adapt-a-roll to use in a Miniature Speed Graphic. I've put maybe a half dozen rolls through it and it's worked fine, until now. I'm suddenly having trouble getting the black slide into it. The slide goes in about an inch and hits something solid, with a "click." If I fool with it for a while it eventually bypasses whatever it's hitting and goes in OK, but it's pretty much unusable right now. I don't see an obvious way to disassemble the device to get to the problem. Has anyone had this problem in the past, or have any experience working on these?

It sounds like the light trap came loose and has slid partway down the darkslide slot. I do not know how to fix it.