Double check your connection parameters.
See what ver of php and mysql the host is running, May or may not be a compatibility issue.
Make sure your storage folder has correct permissions.

jimgwhit said:

Double check your connection parameters.
See what ver of php and mysql the host is running, May or may not be a compatibility issue.
Make sure your storage folder has correct permissions.

in localhost, ver of PHP:5.5.12, MySql:5.6.7, Apache:2.4.9 and in my host ver of PHP:5.4.39, MySql:5.5.42-cll , Apache:2.2.29 . in localhost web runs correctly but in my host i have this error!!is it for this diffrence..?!?! and my connection parameters are right, my storage folder has 0755 permission... please Guid me to solve this problam:(

Go to PHPmyadmin on host and make sure you can access the data there if not then Laravel isn't the problem there is another problem I believe the permissions is 777 but don't quote me on that please double check that somewhere. But laravel needs write access to storage folder. Make sure your config and .env file is correct.
I also found this:
This indicates a php version incompatibility with mysql libraries installed on your webhost. Contact server administrator to resolve the issue.
So verify your host has all required libraries for laravel loaded.

I had the same issue when i upgrade my hosts php version. i just set mysql user password again from cpanel. problem is solved. i think its about upgrading MySQL version and password hash 16-byte to 41-byte.

http://stackoverflow/questions/14612551/