I recorded a conference and yesterday and it had a female speaker and then I stopped it to change to the male speaker. I had an error I couldn't reproduce since but now I get 2 error messages whenever I try to open the file and GB doesn't recognise the audio file I want to now convert to AAC. The first error message states: This file type is not supported. I click okay and then get a second message, it states: 1 invalid regions(s) changed! Once I've clicked those I get this message stating the audio recording is in 8 bit and is unsupported and then GB closes up. I need that file converting into AAC, any help is appreciated.