I haven't done any "serious" WZ editing in years. However, during the time that I did, I figured that JMS had some weird things going on. As haha01haha01 mentioned, their encryption is different from other versions as in it can't easily be predicted, hence the support for JMS is kinda mediocre. HaRepacker may be able to open one JMS WZ file, and be unable to open the others. Or sometimes, more than one encryption is used in the same WZ file. And the second thing that I realized is that many of JMS's "exclusive" sounds exceed the "typical" bit rate from GMS/SEA/KMS. I can't recall any from the top of my head as it's been years, but I remember seeing a few of their login screen music having bit rates that were higher than those of GMS/SEA/KMS. Anyways, back in the days, we had to insert a certain HEX string for certain bit rates. Perhaps, you should try experimenting and figuring out what HEX String you should insert for the bit rate of that sound.
As for the "FAIL" sign, I think it'd be located in Effect.wz. Probably Effect.wz > BasicEff.img. Not certain as I haven't done any WZ editing recently. I am just taking a guess here. Also, what are you planning to do with this? Are you trying to WZ edit jobs in? The best you can do is a skill cover rather than adding an entire job.