Did you accidentally block Google from accessing your web site? Google says you don’t have to worry, while there may be short term damage caused by it, you should recover.
Google’s John Mueller said it should not result in “long term damage.”
Here is how John put it:
So if your hosting company has issues or you slip up and block Google, once Google can crawl again, in the long run, you should be okay.
Forum discussion at Google Webmaster Help.
Image credit to BigStockPhoto for construction hat