Getting error while installing from composer

[saqlain-syed]

I have tried to install using composer.. but I am getting this error below.. I am using PHP 5.6 .. please help!

Your requirements could not be resolved to an installable set of packages.

Problem 1
- The requested package mfn/aws-post-v4-sign No version set (parsed as 1.0.0) is satisfiable by mfn/aws-post-v4-sign[No version set (parsed as 1.0.0)] but these conflict with your requirements or minimum-stability.

[mfn]

Works for me:

~/tmp/test $ cat composer.json
{
    "name": "test/test",
    "require": {}
}
~/tmp/test $ composer.phar require mfn/aws-post-v4-sign
Using version ^0.1.0 for mfn/aws-post-v4-sign
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 1 install, 0 updates, 0 removals
  - Installing mfn/aws-post-v4-sign (0.1): Downloading (100%)
Writing lock file
Generating autoload files

I would suggest to check your composer.json, specifically regarding minimum-stability.

If you can't solve it, please provide your composer.json and the actual command you tried to run.