Error: Timestamps appear as negative numbers or wrap around.
Cause: Old BLF files use 32-bit microsecond timestamps that overflow.
New fix: In asammdf, force 64-bit conversion:

mdf = MDF(input_path, sync_timestamps=True)

For batch processing or automation without a Vector license, the Python library asammdf is the industry-standard open-source tool.

input_blf = r"C:\Data\test_drive.blf" output_mf4 = r"C:\Data\test_drive.mf4"

try: # Load the BLF file # Note: asammdf reads BLF natively but relies on the installed version supporting it print("Loading BLF file...") mdf = MDF(input_blf)

# Save as MF4
# version='4.10' is the most common stable MF4 version
print("Converting to MF4...")
mdf.save(output_mf4, version='4.10', overwrite=True)
print(f"Successfully converted to output_mf4")

except Exception as e: print(f"An error occurred: e")