You tried and there is no error, then I think I am using an incorrect rom or old patch.
However, i finished the game in my 3ds yesterday, and found no errors after the chapter 9.
Name: FIREEMBLEM4
Speed: 35/FastROM
ROM Map: HiROM
Type: 02
Kart contents: ROM+RAM+BAT
Header ROM Size: 32Mbits
Calculated ROM Size: 48 Mbits
SRAM size: 64Kbits (64Kbit)
Actual Checksum: A1CE
Header Checksum: 6562
Header Checksum Compliment: 9A9D
Output: NTSC 60Hz
CRC32: 44AC397C
Licensee: Nintendo
ROM Version: 1.0
Region: Japan