@Kris, I hit my email send limit for the free trial today. I'm trying to get it upgraded, but apparently I have to wait for SendGrid support to approve the upgrade for some reason. Your account was probably created, but it most likely just needs email verification. I can do so for you if you tell me the username you were trying to create.
@dzuhR2BKb3nbMKBGvdMarLDCyoVr2G hey! My username, I'm wanting is @kris but am unable to signup anyway. I'm seeing the same issue on an instance I created too but haven't had the chance to debug.
I had this issue when trying to create my account with the full quote "SoLongAndThanks4AllTheFish". Apparently this name is too long and results in a silent error - the "Register" Button just kept loading. Maybe you have a similar problem?