Hi:
This happened a few times already while monitoring quite lively log in real time, after certain unattended time I found the app in a hang state, the main window is black and the error box over it, but blank (see attached). Is there any log that can trace why is this happening? The log can reach a few dozen million rows in a couple of hours, memory issues?

Yes - probably memory issues.

We have seen this issue before when the process doesn't have enough resources to draw itself.  In this case, it looks like LogViewPlus is trying to show the error reporting dialog, but it can't.  The process has probably run out of memory.  For more information please see the Performance Profile section of the documentation.

I have just got the error report sent, I hope you may be able to give me more insight. An hour and a half of running before the error today.

Thanks for the error report. 

The issue I received appears to be with the GetHDC call.  The issue is probably related to available memory, but I will look into the possibility that objects are not being disposed of correctly or created unnecessarily.