Integritiycheck failed after inline upgrade

Hi,
I've just upgraded my owncloud instance via the webinterface.
The upgrade was from 9.0.1 to 9.0.10. Everything seemed find until it said the following:
Some files have not passed the integrity check. Further information on how to resolve this issue can be found in our documentation. (List of invalid files… / Rescan…)

The list of invalid files is a bit minimalistic. Could some please have and tell what to do or what went wrong?

Technical information
=====================
The following list covers which files have failed the integrity check. Please read
the previous linked documentation to learn more about the errors and how to fix
them.

Results
=======
- core
	- EXTRA_FILE
		- ownloud

Raw output
==========
Array
(
    [core] => Array
        (
            [EXTRA_FILE] => Array
                (
                    [ownloud] => Array
                        (
                            [expected] => 
                            [current] => 29c9a4388f36ddfaea31f5c736642c6e6905b096bef0e67477327250df254a05c8b9bfdc9b5f9c562ee7dda1bcadf05f7c9563251029ef3e9a6010b4dceb2f32
                        )

                )

        )

)

Try moving the extra file out of the owncloud dir,
start integrity check again,
wait until integrity check is through,
and move the file back.

Thanks for the reply. Does the error message imply that the extra file 'owncloud' resides in the root folder?
I can find files with the name owncloud in several subfolders of my installation.

I would Imagine that "core" is the ownCloud core, so its the
/var/www/owncloud
or your equivalent.