An error occured while loading the data. Presumably your log is too large to be processed. (very small log file)

[DL6ER]

Okay, so this is weird. It means your dashboard shows full statistics but the query log page simply doesn't work? I suppose it might be a cache issue, then.

Try the following:

@DL6ER

Try closing the browser altogether and restarting it.

Another possibility is to go to the "Developer Tools" (press F12), go to "Network" and select "Disable cache" (might be named differently depending on your browser). Then reload the web interface of Pi-hole and keep the Developer Tools opened. The first loading might be slow (because no caching will be done), but hopefully it works in resolving your issue.