Merchant Security Updates: Learn how security upgrades may affect your integration at the 2016-2017 Merchant Security Roadmap Microsite
Payments Standard Updates: Beginning March 29th 2017, PayPal will offer a few enhancements that may require integration changes. Read more here: Payments Standard Upgrade FAQ
What is the error that you're getting? Is this happening with API calls or browsing the regular sandbox website? Have you tried clearing the browser cache / cookies?
For future reference, it's a lot easier for people to help you in forums if you provide details about the problem you're having. "I got an error" really doesn't give us much to work with.
and this error
[Error] Failed to load resource: отменено (logger, line 0) [Error] XMLHttpRequest cannot load https://www.paypal.com/webapps/hermes/api/logger due to access control checks.