Is not installing properly, why?

[sanatbek]

I tried to install it by compsor and ran command.
Following errors I got and my php version is PHP 7.1.6.

The "https://bower.herokuapp.com/packages/jquery" file could not be downloaded: SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed
Failed to enable crypto
failed to open stream: operation failed
https://bower.herokuapp.com/packages could not be fully loaded, package information was loaded from tYour requirements could not be resolved to an installable set of packages.

Problem 1
- 2amigos/yii2-date-picker-widget 1.0.7 requires bower-asset/bootstrap-datepicker 1.7.0 -> no matching package found.
- 2amigos/yii2-date-picker-widget 1.0.6 requires bower-asset/bootstrap-datepicker 1.4.0 -> no matching package found.
- 2amigos/yii2-date-picker-widget 1.0.5 requires bower-asset/bootstrap-datepicker 1.4.0 -> no matching package found.
- 2amigos/yii2-date-picker-widget 1.0.4 requires bower-asset/bootstrap-datepicker 1.4.0 -> no matching package found.
- 2amigos/yii2-date-picker-widget 1.0.3 requires bower-asset/bootstrap-datepicker 1.4.0 -> no matching package found.
- 2amigos/yii2-date-picker-widget 1.0.2 requires bower-asset/bootstrap-datepicker 1.4.0 -> no matching package found.
- 2amigos/yii2-date-picker-widget 1.0.1 requires bower-asset/bootstrap-datepicker 1.4.0 -> no matching package found.
- 2amigos/yii2-date-picker-widget 1.0.0 requires bower-asset/bootstrap-datepicker 1.4.0 -> no matching package found.
- Installation request for 2amigos/yii2-date-picker-widget ~1.0 -> satisfiable by 2amigos/yii2-date-picker-widget[1.0.0, 1.0.1, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7].

Potential causes:

• A typo in the package name
• The package is not available in a stable-enough version according to your minimum-stability setting
  see https://getcomposer.org/doc/04-schema.md#minimum-stability for more details.

Read https://getcomposer.org/doc/articles/troubleshooting.md for further common problems.

Installation failed, reverting ./composer.json to its original content.

[tonydspaniard]

@sanatbek can you add the following to the composer.json file?

"minimum-stability": "dev",
"prefer-stable": true,

And then do composer update -o?

There is currently a mess with some stuff due that composer plugin has been removed on latest Yii versions. So, I am not sure why this is happening every now and then.

[schmunk42]

Rather than using

"minimum-stability": "dev",
"prefer-stable": true,

I'd prefer to set

"minimum-stability": "stable",

and use explicit @dev constraints if a package needs it.

Please see also: fxpio/composer-asset-plugin#86 - might be an issue with downgrading.