Data directory (/data) is invalid

Hello guys,

I'm new to this OwnCloud and i'm facing this error when i'm trying to login.

"Data directory (/data) is invalid
Please check that the data directory contains a file ".ocdata" in its root."

"Cannot create "data" directory (/data)
This can usually be fixed by giving the webserver write access to the root directory."

Can anyone help me in solving this issue please. I would really appreciate.
Thank you all.