Similar to:

http://meta.stackexchange.com/questions/129492/unable-to-link-se-accounts-from-careers-profile-but-can-link-to-so-answers

http://meta.stackexchange.com/questions/133686/unable-to-link-se-accounts-on-stack-careers

http://meta.stackexchange.com/questions/90174/unable-to-link-my-so-profile-from-careers

http://meta.stackexchange.com/questions/125286/my-careers-2-0-account-is-not-linked-to-my-stack-overflow-account/125296#125296

I am unable to link to my SE accounts, although yesterday I was able to. I have followed all suggestions on the answers to no avail. It seems that this is still an ongoing bug.