As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF WE PUT THE LG HANDLE TO THE UP POSITION & THEN WE GOT THE GEAR DISAGREE MASTER WARNING MESSAGE & THE PROX SYS FAULT 1 STATUS MESSAGE. RAN THE NON-NORMAL LIST & LANDED AT DSM, THE GEAR NEVER CAME UP. ALL THE GEAR PINS WERE OUT. INSTALLED TARGET FOR PROX SENSOR PX37 RIG, OPERATIONS CHECKED GOOD IAW CRJ900 32-61-05.