Hi,
I'm the developer for Thank Me Later. I have taken a look at your website. I think the problem arises because you have Directory Index listings enabled on your web-server. So Google thinks the two files you have listed are publicly available. These files aren't supposed to be accessed directly, hence why they are returning a 500 error.
You can either:
- Reconfigure your webserver to not show directory index listings; or
- Add robots.txt exclusion for
/wp-content/plugins/thank-me-later
.
Thanks,
Brendon.