That console message is unlikely to be of much meaning or value to anyone other than Apple's Software Engineers. There are lots of things used in common by Safari and Safari Technology Preview including cache files, Bookmark files, and the underlying browser toolkit that comes in the box with OS X/MacOS. Your error could be arising from any of those common elements or potentially something even deeper than that.
There is nothing in this thread indicating what you have already done, and I am not inclined to go looking for a previous thread, but I would start with the simplest things like disabling browser extensions, and deleting the browser cache and history. If that doesn't solve the problem, consider reinstalling OS X/MacOS on the theory there may be a damaged executable somewhere.
