Elastic audio not working - Unknown Exception in Task Manager

I can't get Elastic Audio to work in PT11. It's the last thing preventing me from migrating from PT10. Whenever I enable elastic audio, I get an error for each clip that is sitting on my elastic enabled track - this error appears in the Task Manager. It says Analysing Audio | Unknown Exception (<name of my clip>)



The clip fails to play when any elastic parameters are changed, e.g. if the track is in Polyphonic mode, change the pitch of the clip etc.



Does anyone have any idea what I can do to fix this problem?



I am using PTHD 11.1.2 on PC, I have an RME fireface 800 interface. The PC is a Dell Precision t-3500, CPU = Xeon 3.4 Ghz, 12 Gb Ram, Windows 8 64 bit



Thanks :)