[Startrek (Martin)]

Help , need some advice from Planetary folk out there !!!
Spent an hour or two successfully processing some lunar vistas using Autostakkert 3 and then Registax 6 ( been using them for years without a problem )
Tried to load my 4th image ( 1200 frame AVI file ) , pressed Open and saw the following error message -

Failed opening file C: ..................... frame count:0 fourCC Check limit. The start frame (691) is greater than it equal to number of frames in file (1200)
Photo attached

Rebooted my laptop and tried to Open a few other AVI files , no go , same error

Any ideas what the problem is , never experienced this before
Been using AS and R6 for 4 years now

Thanks