Problem PXE booting Trinity Rescue Kit (TRK) 3.4

After reconfiguring my PXE boot system to boot the Trinity rescue kit, partly by following the official guide, I ran into the following error:

Looks like we 're booting from network, mounting xxxx:/yyy on /trk
/trk/trk3/trkramfs: Permission denied
Something's wrong in startup, dropping to a shell, stop booting

The solution is to modify the permissions on the file trkramfs:

chmod +rx trkramfs

I am not sure why this problem would occur in the latest build.

I was using the Trinity Rescue Kit 3.4 build 367.