Unexpected Error: Failed to construct a huffman tree

I have a .pbix report that I've been working on for several weeks. Up until this morning, it has been working fine. However today when I opened it, I am getting the following:

Due to this I am now unable to edit the report. I cleared the Power BI cache and that did not make a difference. My report is connecting to an on-premise MS SQL server for data. Has anyone ever encountered this/have any idea how to fix it? I really don't want to have to re-create this report from scratch.