Spring Boot application has suddenly stopped compiling

I am developing an application using Spring Boot. It is fairly straightforward. It uses Quartz to schedule Pentaho jobs to import data into a Postgres database. I contains only 1 module(the original, no extras have been added). The project started out using Java 7 but within the first couple of weeks I switched to Java 8. After the switch, everything ran fine(i.e the application would compile and launch). I started coding some new classes and when they were completed, I went to test them and the application wouldn't compile. I got an error stating that Java 8 was the wrong source code. I checked my project structure and both Global and Module compilers were set to Java 8. I did find that Gradle was still using Java 7. I changed Gradle to Java 8 and the error changed. The compile was still failing due to the following errors:

• error: package org.quartz does not exist import org.quartz.*;
• error: package org.quartz does not exist import org.quartz.*;
• error: package org.quartz does not exist import org.quartz.*;
• error: package org.quartz.impl does not exist import org.quartz.impl.StdSchedulerFactory;
• error: package org.quartz.impl.matchers does not exist import org.quartz.impl.matchers.GroupMatcher;
• error: package org.pentaho.di.core does not exist import org.pentaho.di.core.KettleEnvironment
• error: package org.pentaho.di.core does not exist import org.pentaho.di.core.Result;
• error: package org.pentaho.di.core.exception does not exist import org.pentaho.di.core.exception.KettleException;
• error: package org.pentaho.di.job does not exist import org.pentaho.di.job.JobMeta;

Quartz and Pentaho are not being found even though they are set up in the Project Structure:

I am fairly new to IntelliJ so any suggetions on what else to check or how to proceed would be greatly appreciated.