Found an issue at Day -1 of use. I was trying to combine multiple pdf into One but after selecting pdf there was no indication on what to do next... The combine Pdf button was disabled and I keep trying selecting deselecting pdf.. Finally , when I typed a name in input box...Ohh I got to know why the button was disabled.. Strange that after removing name again a proper validation message appeared which should come earlier to help a new user to indicate what's he missing..