Which version is this? If it's the browser version, which broswer are you using and have you already tried clearing your chache?
Click the three dot menu icon in the upper right corner, select "More Tools" > "Clear Browsing Data". Select "Cookies and Other Site Data" and "Cached Images and Files," then click "Clear Data." If that doesn't fix it, I'm not sure I can do much since this since this is the first and only time I've ever seen this error and I haven't been able to replicate it, I'm sorry :( If you don't mind replaying to that point, I would recommend playing the downloaded version.