As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN AVIONICS BAY STR 25R (LONGERON) CORRODED BETWEEN FS 333.00 AND FS 364.00. C-CHECK RO 10/9/2020. REMOVED AND REPLACED MAIN AVIONICS BAY STGR 25R (LONGERON) FROM FS 333.00 TO FS 364.00, REF CRJ900 SRM AND DWG PRESSURE CHECK GOOD, REF CRJ900 AMM. SEE CONTINUE CARD FOR WORK PERFORMED. COMPLIED WITH TASK CARD.