HSL API version 1.2.0 has been in beta-testing phase and it will be finally moved to production use on Monday 4.5.2015.

So, if you are using "prod" version (currently pointing to version 1.1.3) make sure that everything will work after the link is updated to 1.2.0.

Instructions for version 1.2.0 can be found at:

https://www.hsl.fi/en/hsl/open-data