I discovered this accidentally, but while the files manager to open a log is popped (cmd + o), user can still open the about popup, whether by an accidental cmd + h shortcut, or through the menu. At that point, closing the About popup might sometimes work, sometimes not.
But if the user finish to select and open a log file while the About popup is still opened, it seems to completely stuck the Log Viewer: About popup can't be closed anymore, and log seems to not load at all.
All the user can do is closing the Log Viewer completely as it's now unusable.