One of the reason could be the Header part of the QFX / OFX was incorrectly formatted. To resolve this concern, edit the QFX / OFX file as below:
- Open Notepad/Notepad++
- Hovered mouse to File > Open
- Filter the file name from .txt extension to All Files
- Selected the QFX file being imported
- Upon opening the file, create a line break between OFXHEADER:100 and DATA lines
- This resulted to the isolation of OFXHEADER:100 to row 1
- Click Save and retain the .qfx/.ofx file extension