Convert PDF to tiff with Header not found error

I am using your online to convert PDF music sheet then input into PhotoScore, I got first time pass and it is very good! but after that your tool became very slow, some time showed back end busy or not available. when I got the file and down load again, it never work, “Header not found” is the error msg from Photoscore. do you made any change recently in your back end?

thanks,
Gary

@garylu

Could you please share the problematic PDF?