org.drools.template.parser.DecisionTableParseException: Failed to open Excel stream, please check that the content is xls97 format

Question

I have created a new excel file which was in .XSLX format (autosaved). I reopened it and saved as ".XLS", but I still get this error in running my Spring Boot app.

Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'droolsDemoController': Unsatisfied dependency expressed through field 'session'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'getKieSession' defined in class path resource [com/svc/config/DroolsDemoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.kie.api.runtime.KieSession]: Factory method 'getKieSession' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'getKieContainer' defined in class path resource [com/svc/config/DroolsDemoConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.kie.api.runtime.KieContainer]: Factory method 'getKieContainer' threw exception; nested exception is org.drools.template.parser.DecisionTableParseException: [accountEligibility1.xls] Failed to open Excel stream, please check that the content is xls97 format.

I am successfully able to open the file using Excel, it's not corrupted. I am not sure how to fix this error. The excel file is in /resources folder and is being able to located accurately at startup time.