When you build the rulebase any errors or warnings that are detected will be automatically logged in the Error List. Using this list you can see the type of error/warning ( build warning, build error, model warning, model error) and a description of the error. Where relevant, the file that the problem has occurred in will also be listed.
There are two checks that are always performed when you build the rulebase:
a check for multiply proven attributes, and
a check for logical loops.
There are a couple of other optional checks that can be performed when you build the rulebase. See Build a rulebase for more information.
To fix a build error, select the error in the Error List and double-click it. If the error relates to:
a multiply proven attribute, the Rule Browser will be shown. This view lists all the proving rules for the attribute and allows you to navigate easily to the rules within Word or Excel in order to fix them (either by using rule fragments, or by making the attributes not multiply proven). An attribute which is proven by multiple rules, where these rules are not tagged as rule fragments, will not function correctly in the Engine because of the operation of the automatic alternate conclusion in every rule. That is, the closed logic of alternative conclusions will prevent both rules being traversed - the first traversed will close off the possibility of the other form operating.
logical loops, the Logical Loop Check report will be shown. A Logical Loop Check report generates a list of any undefined self-referential rules, ie where an attribute is proved by itself and not defined as a rule loop, in the entire project. The Attribute Chain column in this report shows the chain of connections between attributes resulting in the self-reference. The Participating Rules column shows each of the rules involved in the loop. Generally, loops do not occur in single rules (eg x if x) but more commonly in highly nested layers of rules. Having self-referential rules has the result that those rules can never be fully proved. That is, the rule will repeatedly undergo a question search down the looping branch, cycling endlessly and never locating a base attribute within it. Use this report to identify the loop and then rectify it in your rules. If you are sure that the logic you need to model requires a loop in your rules, you may define the rules as rule loops.
an attribute needing a public name, the xgen file for that attribute will be shown. You will need to add a public name for that attribute in the associated properties file. To do this, select the attribute in the attributes list in the xgen file, right-click and choose Create Public Name In and your properties file from the pop-up menu.
To save a copy of the list of errors:
Right-click anywhere in the Error List window.
Select Copy List.
Open Microsoft Excel or Word (or another authoring tool) and paste the list.
build warning, 
build error, 
model warning, 
model error) and a description of the error. Where relevant, the file that the problem has occurred in will also be listed.