Update: 17 June 2019
As of today the issue is resolved, however you may continue to see this error when submitting new products. You will need to wait up to 3 days for a recrawl. It looks like the issue is not technical but related to an influx of crawl requests. Meaning it delayed Google’s crawler, which then flagged the diagnostics report to flag this as a crawl error, which infact it is due to Google’s crawler not being able to keep up with the amount of requests. This of course is an assumption based on development knowledge and how the issue self resolved over the weekend without any fix from Google directly.
Initial Issue: 13th June 2019
If you are having issues where all images are disapproved or having crawl issues on the 13th of June 2019, then contact Google directly to report the issue: https://support.google.com/google-ads/answer/7218750
A lot of merchants are having this issue today and it’s related to Google’s processing mechanics.