php_redis.dll not working in windows
Just in case it can help someone, I managed to solve the error on PHP 7.1.12 installing the 32 bits DLL.
I was getting the error:
Warning: PHP Startup: Unable to load dynamic library '.../php_redis.dll'not a valid Win32 applicationBut after installing the 32 bits version, the warning disappeared.
To know which architecture of XAMPP/WAMP are you using, visit the phpinfo() and look for the value "Architecture", it was for me on the fourth row, and as expected is had the value x86.
Unfortunately I do not run 64-bit version of PHP to test this, but for PHP 5.3 you can try this dll.
Dll from https://github.com/nicolasff/phpredis/downloads ( php_redis-2.1.3-5.2-vc6-ts-4350b2a.zip ), is working fine with PHP 5.2.17 (32-bit version).
I hope you will solve the problem.