ULS Viewer real-time feeds NOT working

I've had this issue in the Development VM I'm using, where ULS Viewer would never load the logs in real-time from the LOGS folder.

I ended up finding the issue, or at least a solution for my case, in some comments on the Microsoft tool page (here), which was deleting all the old log files. The current one will be in use and won't be deleted, which is fine.

Another workaround was deleting the upgrade*.log files only, but I didn't have any, so the problem was probably in another log file. It seems that if the logs that don't follow the  formatting ULS Viewer expects, RT feeds won't work correctly.