Here is a screen recording. Note my mouse is over the sign in and then as soon as I click it it gives me the error. (I also turned off the retailmenot extension, and I got the same result).
(Click video to play)
Below is a screen shot if it helps, I think it is odd also that I get a translate pop up from Danish to English
(In case you needed the complete url it redirects me to, here it is
https://gopro.com/login?redirect_uri=https%3A%2F%2Fcommunity.gopro.com%2Fservices%2Fauthcallback%2FGoPro%3Fstate%3DCAAAAY_T_md6MDAwMDAwMDAwMDAwMDAwAAAA-LPpYI3rVC5l3Iaq8QGkfqLzyso31PIWxqkmMp0EVj82CXlublUXeZTtBhPBtIr-f6gzzYywQGHwSJ6Qrx2iLzLhK5MoMwDor94X0HmJRuqLRCpAUi7MHb4nJb8s-c0Z2rNGfCK8Mak3hR8Z2eofbgdG0E4JJ0VKYPaYkWzoGecIUBfTFreG7LZUh-s_yfmlht0_47GW2Cms2WJ4jgwzJ6psQJwyst0uuVVXz_hll7LbR3499WUzcfFObI8PZuaItNLbZetJa1J9VfjfMX979PnjqIwggqJA6WhIaZQlXESN.
