RedisSessionStateProvider ERR unknown command 'EVAL'

I was running a version of redis server pre 2.6.

Quick easy way to get redis server for windows is via chocolatey.

Install from here: https://chocolatey.org/

Then get redis using command from here: https://chocolatey.org/packages/redis-64/3.0.501

Then go to C:\ProgramData\chocolatey\lib\redis-64 and run redis-server.exe

You'd then need to install as a service (see notes in C:\ProgramData\chocolatey\lib\redis-64)

OR just get a windows installer msi from here (even easier if you don't mind the version too much i.e. just for development) https://github.com/MSOpenTech/redis/releases

You should upgrade your Redis as @SSED said. You can download 32 bit version of redis here: https://github.com/cuiwenyuan/Redis-Windows-32bit

Also if there is another error "Active machine refused It" you should run redis-server.exe file after downloading it.