Unable to save NXT program I pulled out my NXT recently to tinker around with it. After reconstructing one of the suggested builds, I was writing a small program for it. About halfway through, I needed to leave my work, so I tried to save the file, but I was unable to. I received the following completely straightforward and not confusing error message:



The text of the error message reads

Insane object at BHDP+3C18 in "Arm4Caleb.rbt": {graphics } (0x80): Loop Tunnel DCO )

with Arm4Caleb.rbt being the name of the file. I have failed to find what this error message may be referring to.

I also attempted to save a blank NXT program file; this was successful, leading me to believe that there was something wrong with my particular program. Consequently, I attach an image of the NXT program (I can't post the file because I can't save it):



The program is in collapsed mode so that I can screenshot it; the alternate decision for the largest switch "box" is a use of the C motor; the alternate decision for the medium box is a use of the C motor in the opposite direction; the alternate decision for the smallest box is doing nothing.

It's been a while since I've tried this visual coding stuff; I suppose I have an error somewhere in here? I'm not sure why it would prevent me from at least saving the file, though.
Apparently, all that I was missing was a STOP block at the end of the thread. Hopefully my oversight helps future users.

The STOP block looks like so: