We have an app that is designed to run on a Heroku server that is creating new records in salesforce and also listening to streaming API topics to update our other datastore with changes in those records. We have been using the nforce library with node.js and its been running just fine since late November with no log-in issues to speak of. Either late Friday or Saturday we were updated in sandbox to Spring 16 release and since then am getting an error:
Error: invalid_grant - authentication failure
I have refreshed the user security token and tried that with no success. We did move the app to point at production versus sandbox and had zero issues logging in and creating/monitoring records.
Does anyone know if Salesforce has changed anything in regards to the username/password Auth flow that we need to handle differently? We even tried writing a new app that was just a log-in into the system and that fails the same way. Appears to be an with the upgrade over the weekend.