OK, finally got through the sib file.
I'm not sure what's causing either of the trombone lines to not play, both played fine for me. ... I do see a couple of other things though.
Both the Baritone Saxophone and Baritone Horn staves are not from the S7S Ensemble of instruments - note that some notes are displaying "out of range". They're also not loading the right patches because of it. To fix, add the appropriate staves to the score, copy/paste the content, then delete the old staff.
I also went into the Dictionary and removed the sound ID change for the staccato. This is optional, but I thought it sounded much better when Sibelius was not playing the actual staccato samples from the S7S library.
It may just be that you're not done writing in that file, but the suspended cymbal rolls' noteheads are triggering the short cresc sound. Again, probably just not done yet.
Other than that, it appears your merging of templates went fine, I don't see anything that sticks out to me.
Oh, I did just see that your SnareLine Manuel has a few errant note entries in the mapping (it's not because of a glitch in the merging process). To fix, go to Home > Instruments > Edit Instruments > - VDL Template 7.0a > Drumline Battery > SnareLine Manuel, click Edit Instrument, click Edit Staff Type. Delete the entries as I've marked them in the attached image (all 4 will be assigned to F#1).
Hugh