If you have validation errors about your AMP pages, the Google Search Console/Webmasters Tools will be likely to advise you by email and you will see these errors listed in the AMP pages section.
In such case the first thing to do is to take advantages of JAmp settings to exclude HTML tags, attributes, etc that are responsible of invalidating your AMP pages.
After that you may expect to see errors in Google Search Console/Webmasters Tools immediately gone, but unfortunately that's not the case.
Notice that even after errors have been fixed, Google Webmasters tools/Search Console will continue to show errors just like before.
The Google Webmasters tools/Search Console requires a lot of days to refresh and often it continues to show past errors even if fixed.
If you are using the new Google Search Console Beta, notice that Google added a feature to speed up re-validation of AMP pages, even if still not working really well at the time of writing this.
You can ask Google to re-validate your AMP pages, in the case that the new Google Search Console Beta works well you should receive an email that the validation has been started.
After some days errors will still be there but the number of pages affected should be decreased and reported as 0 zero.
Probably this report will be fixed better in the future when the new Google Search Console will be stable.
In the old Webmasters Tools AMP errors could be removed definitely after a lot of days.
After that the re-validation has been completed, fixed errors could even still be counted even if marked as fixed in the validation column. This is a bug of the new Google Search Console Beta that will be hopefully fixed in the stable release, being now a false positive.
The report above has indeed no more errors, being 2 errors re-validated and flagged as 'Looking good' and another error now counting 0 pages.