I bought a Mega2560 today and was going to upload some code to it. The code required arduino ide > 1.6 so i updated my 1.0.5 to 1.8.13. And it couldn't upload, so I tried burning a bootloader with my USB-ISP. It failed. Then I got my uno to use it as ISP but now the IDE can't even upload code to it, which 1.0.5 did before. Downgrading to 1.0.5 does not solve anything either, the IDE still says there is a timing issue.