Figuring out what is going on with Reports can be...interesting.
A couple of suggestions for diagnosing issues:
(1) Save the file on the ESM as well as emailing it and see if the file gets generated. This narrows the issue down to email if the report file turns up.
(2) Click on View right after clicking Run Now and see if the report job runs. There can be a noticeable delay before the report starts running so be patient.
If you get nothing out of these then try starting again with a fresh report definition.
Ya I ended up just remaking the report. I guess the initial version was corrupted. Very odd that it happened after only two days.