Error onestepcheckout

[webm_nickey]

Hello,

I have installed the following extention on a magento website:

https://www.magentocommerce.com/magento-connect/one-step-checkout-42.html

It works fine but when you want to add a new address on de checkoutpage you get the following error.

Someone an idea where this problem come from?

[gmarti]

Check the system log or exception log.

This files are located in var/log folder.

[webm_nickey]

Thanks there i find the following error:

2016-09-28T10:06:41+00:00 ERR (3): Recoverable Error: Argument 1 passed to Mage_Core_Model_Store_Group::setWebsite() must be an instance of Mage_Core_Model_Website, null given, called in /home/fekoconv/public_html/app/code/core/Mage/Core/Model/App.php on line 665 and defined in /home/fekoconv/public_html/app/code/core/Mage/Core/Model/Store/Group.php on line 275
2016-09-28T10:06:42+00:00 ERR (3): Warning: array_key_exists() [<a href='function.array-key-exists'>function.array-key-exists</a>]: The first argument should be either a string or an integer in /home/fekoconv/public_html/app/code/core/Mage/Core/Model/Translate.php on line 569

Can someone help me a little bit farther?

[GauravMehta04]

@webm_nickey Go on path app/etc/ and delete use_cache.ser file. 

[webm_nickey]

I don't have a file named use_cache.ser in that folder.

[webm_nickey]

I find the problem.

The Company name field is required, but that field was not on the checkout page.

The problem is fixed.

[gmarti]

Very good!!! I'm glad you've been able to solve.

Please share your solution, which files you have reviewed or modified to serve as a support to other users.

Thank you.