On January 27, some people ran into errors when trying to sign up for Buffer. This mostly happened if you were coming from a partner link or certain marketing pages — signing up directly from buffer.com generally worked fine.

We tracked it down to a mismatch in how we handled referral tracking codes. A change from a few months back meant some signup links were passing a value in a format our backend didn't expect, which caused it to error out. We've since updated the signup flow to handle both formats properly.

If you hit this error, trying again now should work without any issues. To prevent this from happening again, we're adding automated tests around our referral code tracking to catch these kinds of regressions before they reach production.