# Getting error while running composer install command

**URL:** <https://www.phphelp.com/t/getting-error-while-running-composer-install-command/36228>\
**Category:** General PHP Help\
**Created:** [July 31, 2024, 4:25pm UTC](https://www.phphelp.com/t/getting-error-while-running-composer-install-command/36228 "2024-07-31T16:25:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rahulhemant84](https://www.phphelp.com/letter_avatar_proxy/v4/letter/r/ecd19e/32.png) [@rahulhemant84](https://www.phphelp.com/u/rahulhemant84)\
**Post date:** [July 31, 2024, 4:25pm UTC](https://www.phphelp.com/t/getting-error-while-running-composer-install-command/36228/1 "2024-07-31T16:25:38Z")

</div>

Hi,

I am new to php and trying to setup an application called [https://cachethq.io/](https://cachethq.io/) which is developed in php.  
On trying to install dependencies using command “composer install --no-dev -o” I am getting error:-

**Script @php artisan package:discover handling the post-autoload-dump event returned with error code 255**

While debugging the application also I am getting below error:-

**PHP Fatal error: During inheritance of ArrayAccess: Uncaught ErrorException: Return type of Illuminate\Support\Collection::offsetExists($key) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in D:\cachet-2.4.1\vendor\laravel\framework\src\Illuminate\Support\Collection.php:1911**

Any help or direction to fix the issue please?

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<div class="post-metadata">

**Author:** ![reddig.hamburg](https://www.phphelp.com/user_avatar/www.phphelp.com/reddig.hamburg/32/4389_2.png) [@reddig.hamburg](https://www.phphelp.com/u/reddig.hamburg)\
**Post date:** [June 16, 2025, 8:00am UTC](https://www.phphelp.com/t/getting-error-while-running-composer-install-command/36228/2 "2025-06-16T08:00:47Z")

</div>

There might be issued with the software versions you are using.

It seems like the 2.4 version was built on php 7 and might be incompatible with any php 8.x while the 3.x of the software is not yet ready for production.

Which php and extensions are you running?