Colleagues.
I have a page in PHP that until yesterday was working properly, but today is giving 500 error. It already deletes all the code and left only the opening tag < ? php and still the error persists, but when I also remove the tag, the page appears (blank, since there is nothing else in it). I remember some time ago that it may be the space that occurs before the opening tag, that in certain programs it is possible to see this space, but I can not remember the name of the program. I'm using it in Netbeans.