Before we troubleshoot our first error, we need to create one. Let's start by making a bad change to the My First Commission Rates table that we created in the Import Your Data article. Click on Define at the top of the page, then click the Data Tables button. Select the Commission Rates table structure and click on "My First Commission Rates Table" on the left side. The Import Your Data article walks through this navigation in more detail.
Scroll down the table until you see the row with Commission Rate ID and Duration 1. Check the box next to it, then click the Remove Selected button at the bottom. Click the Save Table button in the upper right. It's fairly common when implementing new plan codes to miss a reference like an entry in a supporting table, so this should create a fairly typical error.
Now we want to run our model. Click on Define at the top of the page then click on the Projection Templates button. Click on My First Projection Template. See the Run a Projection article for a more detailed walkthrough. Before we run it, let's assume we already know an error will occur and alter the settings. Click the (Edit) button next to the settings at the top of the screen (to the left of Assumption Sets).
Enable the setting Output All Results. This setting will slow down the runtime, but it makes it much easier to debug the results. Our model is very small (1 model point per product, 1 scenario, only 4 products), so it will still complete very quickly. If your model is significantly more complex, it may be wise to create a smaller product set, a smaller model point file, or limiting the scenarios run. Click the Save button.
Click Create Projection, then click Create. Finally, click the "Validate & Run" button in the upper right.
When it finishes, it will display "Completed with Error(s)". Click the View Run Logs button.
This screen gives basic information on loading files into SLOPE, running scenarios, and errors. Near the top of the log, you'll see a reference to our error. It clearly states that the error was caused by the lack of an entry for Commission Rate ID LIFE and Policy Year 1 in My First Commission Rates Table, and that this happened in the variable Commission Rate of the Term Life product.
Now, let's look at the Error Report dashboard. Click on the Dashboards button in the upper right, then the Error Report dashboard on the left side.
If you scroll down to the bottom of the page of the Error Report dashboard, you will see a section with the heading Model Point Errors. The first error listed occurs at time -107 for the variable GAAP Acquisition Expense Per Policy for the Term Life Product. On the far right-hand side you will see that the error is driven by the Commission Rate variable. The details show that there is no data that references Commission ID LIFE and Policy Year 1 in the Commission Rate table. 
You can click on the text in the Error column, which will bring up another window that will allow you to debug the formula. Click on Debug Formula, which will open up a second Debug tab, where you can drill down into the formulas and data driving the error.
At the top of the page, you will see the name of the variable that you are viewing, Gaap - Acquisition Expenses Per Policy. Note that there is a dropdown menu for the variable name which enables you to scroll down and select other variables within the model that can be viewed within the Debug view. On the left-hand side of the page, you will see that the Debug view refers to Scenario 1 and Time -107. These are both also dropdown menus where you can select which Scenario and Time Index you would like to view.
The Debug view shows the components in the formula for the variable that you are viewing. Above each component name, there is a value displayed in red corresponding to the formula result. At the bottom of the page, the Relationship View is displayed, which is consistent with the view shown when building your Product variables. Note that you can double click on the icons for input and output variables related to the formula in the Relationship View and you will be taken to a Debug view for that variable.
When you look at the variable Commission Rate, you can see that the value shown is "No Results Available". You can click on the result in red and it will take you to the Debug view for Commission Rate. At the top of the formula view, you will see the Table Commission Rate with a red box next to it. You can click on the red box to view the table. In this example, you can also click on the Plan Code Table - Life to view the plan code table which will tell you that the Commission Rate ID, which is used as a lookup in the Commission Rate table, is LIFE for Plan Code LT10 (a field that was provided in the Model Point File you uploaded previously).
If you click on the My First Commission Rate table, you will see that the row for Policy Year 1 for Commission Rate ID LIFE is missing. You can then add that column to the table, save the table, then rerun the model.
If you select Re-Run, you will overwrite the results within the model. This is common practice as you are working through the process of debugging a model.
If you want to change any parameters of the model run, such as uploading a new model point file or referencing different tables, you can select the Duplicate button. Clicking this button will default to a checkbox that will discard the existing model results. If you would like to keep the previous run's results, you can uncheck this box. Clicking on Duplicate will bring you to a screen similar to the Projection Template screen that allows you to adjust the parameters for running the projection.
In practice, once you have made a correction and have rerun the model, you may need to complete this process multiple times as you debug all the errors that may appear, until the model run shows as complete without any errors.