Plex 1.15 and above is going to need glibc 2.14.1. Debian Wheezy is 2.13
Your options for minimum compatibility is to upgrade to Debian/Devuan Jessie or try and upgrade just your libc6 packages from Jessie.
I spun up a wheezy VM to provide the steps to upgrade libc6 (glibc) from Devuan Jessie. Before you do this, make sure you have backups. I only tested this on a VM. Plex Media Server was able to start once I upgraded.
Instructions to add Jessie sources and upgrade libc6:
Add the Devuan Jessie apt repoistory to your apt sources.
Edit /etc/apt/sources.list and add the following two lines:
deb http://auto.mirror.devuan.org/merged jessie main contrib non-free
deb-src http://auto.mirror.devuan.org/merged jessie main contrib non-free
Create/Edit the /etc/apt/preferences and add a Pin to for Jessie to only install packages you specify:
Package: *
Pin: release o=Debian,n=wheezy
Pin-Priority: 900
Package: *
Pin: release o=Devuan,n=jessie
Pin-Priority: 100
Run: apt-get update
Install the Devuan Keyring and select Yes to install from unknown sources:
apt-get install devuan-keyring
Run apt-get update again to pull in the new keys:
apt-get update
Install libc6 and libc6-dev from Devuan Jessie:
apt-get -t jessie install libc6 libc6-dev
These instructions are in the pcloud link from the first post:
