[SOLVED] Weird Error: Please Help!

I was making a new update for RaolCraft 3 when I met another error.

I haven't added nothing new, only crafting recipes.

Initially it sayed that the error was a biome, but, after removing it, the problem wasn't fixed.

Error log:

Executing gradle command: clean runClient
Microsoft Windows [Versione 10.0.15063]
(c) 2017 Microsoft Corporation. Tutti i diritti sono riservati.
C:\Pylo\MCreator175>cd forge
C:\Pylo\MCreator175\forge>SET "JAVA_HOME=C:\Pylo\MCreator175\jdk64\"
C:\Pylo\MCreator175\forge>SET JAVA_EXE=%JAVA_HOME%\bin\java.exe
C:\Pylo\MCreator175\forge>SET PATH=%JAVA_HOME%\bin\;%PATH%
C:\Pylo\MCreator175\forge>gradlew -Dorg.gradle.jvmargs="-Xms512m -Xmx1641m" clean runClient 
This mapping 'snapshot_20161220' was designed for MC 1.11! Use at your own peril.
#################################################
         ForgeGradle 2.2-SNAPSHOT-eb2e450        
  https://github.com/MinecraftForge/ForgeGradle  
#################################################
               Powered by MCP unknown               
             http://modcoderpack.com             
         by: Searge, ProfMobius, Fesh0r,         
         R4wk, ZeuX, IngisKahn, bspkrs           
#################################################
:clean FAILED
BUILD FAILED
FAILURE: Build failed with a* What went wrong:
n exception.
Total time: 28.007 secs
Execution failed for task ':clean'.
> Unable to delete file: C:\Pylo\MCreator175\forge\build\retromapping\replacedMain.rangemap
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
C:\Pylo\MCreator175\forge>
Task completed with return code 0 in 28651 milliseconds