I am having this error flood my terminal and make it impossible to debug. Is there a way to silence this warning? This error only generated when I included a scrollToBottom() on my TableWidget.
It would be much better if some of your actual code would have been available.
The reason you are seeing this is that you are using a different type of threading than QThreads . That is in general not advisable, but it is not illegal. There are three things that you will have to take care

All calls should end up being executed from calls within a QThreads object
All data passed through the signal-slots mechanism should be made such that there are no references/pointers to objects owned from a non-QThread.
Setup connections between object that receive call from non-QThreads to emit signal that are received with either Qt::QueuedConnection or Qt::BlockingQueuedConnection connection type.
How to suppress warning QPixmap: It is not safe to use pixmaps outside the GUI thread