(blank) Fatal Error when activating plugin

I have a series of plugins that I have been working on and they all work fine with versions 2.6 and under. In 2.7, however, when I activate the plugin it says:

Plugin could not be activated because it triggered a fatal error.

And that is it. It does not actually report what the error is. I have checked error logs, etc.. there is nothing.

Not sure if it is helpful, but the error data that gets appended to the URL is:
&_error_nonce=e5da409309

Any help is greatly appreciated!