So, I've tried installing forge for 1.7.10, 1.8,1.8.9, 1.10.2, and 1.12 using both the recommended and latest versions in both the normal and windows installer, and I always get this error. This snip is specifically from the 1.7.10 installer. No one has tried to help me on the minecraft forum besides telling me to run the windows installer as administrator, but that didn't do anything. No one else has gotten a fix to this problem from what I've seen.