Please visit in Backend [Find Partners & Extensions] section. Move your mouse over the links and check the URL's. All links point to Magento Connect which is wrong. When you click on [Visit Magento Marketplaces] button you should visit the Marketplace for Magento 2.

Magento Connect a resource for M1 extensions will be closed on September the 15th.
@ADDISON74 thank you for your report.
Please use the issue reporting guidelines to report an issue. Include the steps required to reproduce, the actual result, and the expected result.
Steps are already mentioned in my initial post. Here they are again:
1) Please visit in Magento 2.1.8 Backend [Find Partners & Extensions] section (see my image above).
2) Move your mouse over the links marked by red lines and check the URL's.
ACTUAL RESULT
EXPECTED RESULT
@ishakhsuvarov @naydav hey guys!
Please excuse me for mentioning you directly, but this issue seems rather time-sensitive and I'm not sure whose responsibility this is.
Could you please take a look at this and maybe pass along to whomever appropriate if necessary?
I suspect that the old URL will have a redirect to the new marketplace installed anyway, but still: it's better to be safe than sorry.
Hey @korostii
Looking for information regarding this one. I will update when I have details.
Thanks.
@korostii @ADDISON74 Some of the links mentioned already perform a 301 redirect, others will start redirecting on the September 15th so this should not be a major issue.