Key column 'FK_UserQuestion' doesn't exist in table error
Your foreign keys have the wrong format. The syntax should be:

FOREIGN KEY &lt;name&gt; (column_1, ..., column_n)
REFERENCES &lt;parent table&gt; (column_1, ..., columns_n)


In your case:

FOREIGN KEY FK_UserQuestion (UserID)
REFERENCES QA.Users (UserID)


I.e.

CREATE TABLE QA.Question
( QuestionID int AUTO_INCREMENT PRIMARY KEY
, UserID int
, Question varchar(65535)
, FOREIGN KEY FK_UserQuestion (UserID)     
  REFERENCES QA.Users (UserID) 
) engine = INNODB;


A similar change for QA.Answer should also be made