Q:When I use the Transformation modules, I get the error "Too many iterations of Transformation calculations". I have repeatedly corrected and checked the data, but I still have the same problem. How can I solve this problem?

A: This most likely reflects that you have set up a model with unresolved feedbacks. For example, if one module produces electricity but another module further down in the tree then consumes electricity. I recommend playing around with the Settings found on the Calculations tab of the Settings screen. In particular, it sometimes helps to uncheck the boxes marked Check for surplus production and Check for unmet requirements. See attached screenshot.

This usually is sufficient to get the model calculating. At that point you can check your energy balance to see which particular fuels have surplus production or unmet requirements. You can then think about where it is necessary to use the iterative calculations to try and resolve feedback loops. You may decide that for some fuels there is no need for feedbacks. This can be especially important when dealing with secondary fuels that are imported. In those cases you can review the Unmet Requirements variable under the Resources\Secondarybranch. I recommend setting this variable's value to MeetWithImports unless you know you definitely want to have unmet requirements met with upstream modules i.e. by setting it to MeetWithUpsteamModules. (Use the orange E button to the right the expressions to quickly set values for this variable.