I know this is an older version, but it looks like you misconfigured your nginx on the migration
forge-1.7.10-10.13.4.1614-1.7.10
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Powered By MCP:
http://modcoderpack.com/
Searge, ProfMobius, Fesh0r,
R4wk, ZeuX, IngisKahn, bspkrs
MCP Data version : unknown
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:extractMcpData UP-TO-DATE
:getVersionJson
:extractUserDev UP-TO-DATE
:genSrgs SKIPPED
:extractNatives UP-TO-DATE
:getAssetsIndex
:getAssets
:makeStart
[ant:javac] warning: [options] bootstrap class path not set in conjunction with -source 1.6
[ant:javac] 1 warning
:downloadMcpTools FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':downloadMcpTools'.
> java.io.IOException: Server returned HTTP response code: 500 for URL: http://files.minecraftforge.net/fernflower-fix-1.0.zip
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
Total time: 11.399 secs