Unable to register for expert

On this page https://www.codeponder.com/register
This error shown in the console when forms are filled and create account clicked:

`Error: GraphQL error: Cannot read property 'includes' of undefined `

the post data:

```
{
"operationName": "RegisterMutation",
"variables": {
"input": {
"username": "qweee",
"email": "myemail@gmail.com",
"password": "qweee"
}
},
"query": "mutation RegisterMutation($input: RegisterInput!) {\n register(input: $input) {\n errors {\n path\n message\n __typename\n }\n __typename\n }\n}\n"
}
```

Start by reproducing the failure on https://www.codeponder.com/register with the shown username, email, and password, then inspect the RegisterMutation request and its returned error. Trace the registration entry point from the page and verify that account creation completes without the `includes` error and the mutation returns no registration error.

Written by the indexing model from the issue text.