I am having this same issue. Running Max2play 2.45 on a Pi 3B.
Previously had everything working great… then a couple days ago I could no longer access the web administration.
I made a new image, restarted the pi. Max2play is running (and I updated to 2.45) but when I try to install Squeezebox Server (either Nightly 7.9 or v7.9.0) it starts unpacking and then quits. I quickly see an error notice that the version doesn’t exist, then the yellow box disappears.
Any help is appreciated.