1 - If the error message is correct, then you've got "spec corruption" in you bsfn, N5542750. Basically, the blc header is a spec record (in the jdeblc file) that is like a header record for a function in a bsfn object. Whatever machine you are running this on is missing a spec record for the N5542750.
2 - The good news is that this is probably just a change management error. Since this is a custom object, either N5542750 was not checked in, failed on check in, was not transferred (? dev to crp, for example), failed on the transfer, or was not included in a package and deployed. My guess would be that the programmer forgot to list it on a transfer sheet along with whatever program you are running that calls it. So you've deployed the application (P* or R*), have started to use it, it calls N5542750, but the bsfn is not there. Check the checkout log application (P9882) to see if the object has been checked in and transferred correctly, then redeploy in a package.
owguru (at least I'm trying