Google occasionally blocks traffic from or through the library's proxy server, in which case, you may see the following error message: "ERROR for site owner: Invalid domain for this site key."
Google institutes the block as a security measure during times of high or unusual traffic through the library's proxy server. Unfortunately, Google does not provide a way for libraries to contact them when this or any other problem occurs, so it is impossible to speculate when this block will be lifted, but generally it does not last more than a few days.
The block affects users when accessing Google Scholar using the library's proxied link from off-campus (ie, the Google Scholar link on the Database A-Z). On campus usage is generally unaffected.
To circumvent this problem, you should use Google Scholar's direct link and configure your settings to access Oakland University Library resources. You can find instructions for customizing your Google Scholar settings here.