Unable to compute due to missing data

[HeinrichK]

Eviews 6

I'm trying to solve a model developed by external consultants for my organisation. I have not been modelling for many years and not knowing Eviews that well I'm unable to solve this problem, I think I know what it is but is unsure how to fix it. I hope someone can assist urgently.

The message I receive states "2012Q3 NA generated for vol_pop_sa" ... "solve terminated - unable to compute due to missing data in dlog(....)"

The equation I'm trying to model is: dlog(vol_pop_sa) c log(vol_pop_sa(-1)) ...

The underlined area is where I think the problem is. The variable vol_pop_sa is the seasonal adjusted dataset. It is what I want to forcast as well as a variable in my equation. I assume that the idea is to use the forecasted values in the future for the lagged variable where they don't exist. This seems to work for the period 2010Q2 to 2012Q2 but not after that period.

Any ideas or thoughts on what I need to do will be much appreciated.

Thanks
Heinrich

[EViews Gareth]

I think we'll need to see your workfile.