Please tell us which hardware you are using and which software versions (Max2Play buster/stretch image and version). Have you connected your device via Ethernet or Wifi? What steps did you take to set up Max2Play?
I’m on Version 2.53 on Raspberry PI 4B 4GB. I’ve tried both wired and unwired connections.
It’s been so long since I’ve written to the SD card in the Pi that I’ve forgotten the specific steps used to setup. The crux is that every tab in the web app will open minus the two I mentioned. The player works fine. Don’t really want to have to rewrite to the card if possible, so wondering if this is a typical problem with an easy fix.
Unfortunately, I haven’t encountered this problem yet, so I can’t offer you a simple solution. The best thing would probably be to burn a fresh image onto the SD card. The problem really sounds like a broken image.