Alpha Channel has suddenly stopped working

[Marcelbaettig]

I have been making up a number of Quicktime alpha channel films using both Gopro+alpha and animation codecs. It has been working fine for days and all of a sudden the alpha channel is not working and its exporting as a solid black background. I have not changed anything that I am doing and have spent the last two hours trying to figure out the problem.

Does anyone please have any ideas?

Thank you

[Marcelbaettig]

All sorted now thanks...a silly mistake by me! arghh!!!