Microsoft Office Online [Server Error in ‘/op’ Application.]

Hello there;
I started to get the fault this day. Only when Microsoft Office Online is selected gives an error.

Messages displayed on the site:
We’re fetching your file…
Please wait a moment while we retrieve your file from its home on the internet

Background error output:
Runtime Error

Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.

Details: To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a “web.config” configuration file located in the root directory of the current web application. This <customErrors> tag should then have its “mode” attribute set to “Off”.

<!-- Web.Config Configuration File -->

<configuration>

    <system.web>

        <customErrors mode="Off"/>

    </system.web>

</configuration>

Notes: The current error page you are seeing can be replaced by a custom error page by modifying the “defaultRedirect” attribute of the application’s <customErrors> configuration tag to point to a custom error page URL.

<!-- Web.Config Configuration File -->

<configuration>

    <system.web>

        <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>

    </system.web>

</configuration>

Google documents are available.
Should we wait for an update to improve the situation? Do I have to do something to fix it?