Error Code 56: Failed Core Process

I have created an Excel spec using Pinnacle Community and hope to convert that to a define.xml file using the "Generate Define" tab. To test out the functionality, I have only included 1 dataset and have filled out all the tabs in the Excel. I wanted to confirm I am completing the Excel properly before I replicate what I've done for every dataset. I then tried to upload the Excel to generate the define.xml, but I keep receiving the same error code:

"Error code: 56 message: Failed core process.","isError":true,"message":{"current":0,"error":{"cause":{"cause":null,"localizedMessage":null,"message":null,"stackTrace":[{"className":"net.pinnacle21.define.util.Define21StandardHelper","fileName":"Define21StandardHelper.java","lineNumber":34,"methodName":"getPrimaryStandard","nativeMethod":false},{"className":"net.pinnacle21.define.parsers.xml.ParsedStudyToStudyMapper","fileName":"ParsedStudyToStudyMapper.java","lineNumber":114,"methodName":"mapStandardNameAndVersion","nativeMethod":false},{"className":"net.pinnacle21.define.parsers.xml.ParsedStudyToStudyMapper","fileName":"ParsedStudyToStudyMapper.java","lineNumber":105,"methodName":"mapStudy","nativeMethod":false},{"className":"net.pinnacle21.define.parsers.xml.ParsedStudyToStudyMapper","fileName":"ParsedStudyToStudyMapper.java","lineNumber":70,"methodName":"map","nativeMethod":false},{"className":"net.bootstrap.api.define.DefineUtils","fileName":"DefineUtils.java","lineNumber":59,"methodName":"lambda$0","nativeMethod":false},{"className":"rx.internal.operators.OnSubscribeDefer","fileName":"OnSubscribeDefer.java","lineNumber":46,"methodName":"call","nativeMethod":false},{"className":"rx.internal.operators.OnSubscribeDefer","fileName":"OnSubscribeDefer.java","lineNumber":35,"methodName":"call",%"

I've narrowed this down to an issue with the ValueLevel tab of the Excel spec, but I can't figure out why I'm getting this error. I'm new to generating define.xml, so I haven't filled out the ValueLevel tab before, but I don't see anything wrong with it based on the little guidance I was able to find online. Any help would be greatly appreciated!

Thanks,
Ariel