Some tools embed the flash package inside the .exe itself (self-extracting). Those are larger (2-4 GB). If you have a small MSM tool (under 100 MB), it requires an external flash package.
The MSM Download Tool is picky about where its files are located. Common culprits include: The firmware files aren't in the same folder MsmDownloadTool.exe The firmware is still zipped , so the tool can’t read the or image files. The file path is too long Flash Package Does Not Exist Msm Download Tool