You're likely correct that it's a problem with the latest LinkedIn API update. We've been monitoring the plans closely, but there was no way to test ahead of time. We're shooting to have the 6.4 release out today, which will ensure compatibility with the latest LinkedIn changes now that we can actually test against it.
The update that LinkedIn performed earlier this week severely crippled it's API. Now, only a very small amount of data is able to be retrieved for a user.
For a short-term fix (before our update), I'd recommend going to the Profiles area in JFBConnect and checking the fields you are trying to import from LinkedIn. Remove (set to 'None') any of the fields that are not on this list below:
developer.linkedin.com/docs/fields/basic-profile
Our update will be removing the disallowed fields and making some other compatibility improvements, but simply limiting your site to importing the allowed fields should be all that's necessary for now.
I hope that helps, but please get in touch if you run into issues. We'd also love to hear if fixing the profile import fixes the problem as well.
Thanks,
Alex