Here's what composer had to say...
C:\>composer create-project flarum/flarum C:/Flarum --stability=beta
Installing flarum/flarum (v0.1.0-beta.6)
- Installing flarum/flarum (v0.1.0-beta.6)
Loading from cache
Created project in C:/Flarum
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
Problem 1
- flarum/core v0.1.0-beta requires illuminate/support 5.1.* -> satisfiable by illuminate/support[v5.1.1, v5.1.13, v5.1.16, v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41, v5.1.6, v5.1.8].
- flarum/core v0.1.0-beta.2 requires illuminate/support 5.1.* -> satisfiable by illuminate/support[v5.1.1, v5.1.13, v5.1.16, v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41, v5.1.6, v5.1.8].
- flarum/core v0.1.0-beta.3 requires illuminate/support 5.1.* -> satisfiable by illuminate/support[v5.1.1, v5.1.13, v5.1.16, v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41, v5.1.6, v5.1.8].
- flarum/core v0.1.0-beta.4 requires illuminate/support 5.1.* -> satisfiable by illuminate/support[v5.1.1, v5.1.13, v5.1.16, v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41, v5.1.6, v5.1.8].
- flarum/core v0.1.0-beta.5 requires illuminate/support 5.1.* -> satisfiable by illuminate/support[v5.1.1, v5.1.13, v5.1.16, v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41, v5.1.6, v5.1.8].
- flarum/core v0.1.0-beta.6 requires illuminate/support 5.1.* -> satisfiable by illuminate/support[v5.1.1, v5.1.13, v5.1.16, v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41, v5.1.6, v5.1.8].
- illuminate/support v5.1.8 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.6 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.41 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.31 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.30 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.28 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.25 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.22 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.20 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.2 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.16 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.13 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- illuminate/support v5.1.1 requires ext-mbstring * -> the requested PHP extension mbstring is missing from your system.
- Installation request for flarum/core ^0.1.0 -> satisfiable by flarum/core[v0.1.0-beta, v0.1.0-beta.2, v0.1.0-beta.3, v0.1.0-beta.4, v0.1.0-beta.5, v0.1.0-beta.6].
To enable extensions, verify that they are enabled in those .ini files:
- C:\php-5.6.28\php.ini
You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.