Huh. It looks from your gif like your steps are correct, I don’t know why you are getting extra lines off the top of my head. Options:
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If erasing the lines, gets you up and running then OK. You can solve the problem of where/why they are being generated separately, I am Mac and know nothing about PC but I hear a lot about having to run the installer as administrator whatever that means and the odd problems that windows 10 can cause.
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Redraw the whole thing with @DaveR 's sage advice which would be a great learning experience and give you a chance to fix the clocking of the two circles that we discussed earlier in the post.
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If you’re in a bad pinch for time tell us what the chamfer dimensions are and I can post a correct model. This is “giving you a fish” option I would discourage but I have loads of deadlines in my life and am sympathetic.
As far as extensions for solid tools solid inspector and Eneroth Solid Tools are both good places to start.
I do lots of “save as” as my models progress, particularly before big extension operations, that way it’s easy to get back to a good starting place if things go awry. But I use ctrlZ too 