Troubleshooting NaNs in the Jacobian

Hello,

I’m attempting to solve an NK Model with two production sectors, but it tells me that there are NaNs in the Jacobian. This isn’t the first time I’ve run into this problem, but it’s always such a pain trying to figure out what exactly is wrong. Could someone take a look at this and let me know what’s wrong with this particular file? Additionally, does anyone have tips on how to best troubleshoot this problem in the future?

Thanks!
Biased_Infl.mod (5.85 KB)

In the unstable version, I get

[quote]ERROR: If the model is declared linear the second derivatives must be equal to zero.
The following equations had non-zero second derivatives:
* Eq # 4[/quote]

Check that equation.