I have the same problem. I have my lic file with my username working with the app ,checked all the spaces, null bytes... everything. Still still no luck.
A note to the devs. You should make a small standalone executable that generates the license file and make the PHP validation call that exe and get the results like that, since PHP seems to be the wrong tool for the job. That's just my idea, but whatever.
Is my signature cool enough for you?