I've been working on updating my mod from 1.15.2 to 1.16.5 lately. As such, I have needed to check the net.minecraft files frequently to figure out some of the differences between the two versions. However, while I have been doing this, I have encountered several files that I cannot access. When I try to open them either through the file menu in Eclipse or by attempting to open a declaration, I am instead met with an error as seen in the attached image. This is really holding up progress in this update, so I appreciate any help with it.