Working now. Not sure what happened earlier, but it is compiling now without any issues.I cannot guarantee that all models will compile and/or work, since they are untested, and I don't have any up-to-date binary blobs for any of the other models, but I can confirm that the RT-AC88U one does build properly - I'm running it myself.
No one here will be able to help you without any actual details as to the error message however.
Thanks, Merlin for all that you do. Get well soon!!!