MCreator Setup failed

I downloaded MCreator and it opened, successfully finished the first step, but failed the second. I've tried it again many many times, but it didn't work. Here was the error message:

   
Executing gradle command: cleanCache clean setupDecompWorkspace --refresh-dependencies
Build info: MCreator 1.8.1, 64-bit, 8144 MB, Windows 10 - cmd, JVM 1.8.0_172, JAVA_HOME: C:\Users\igmck\Desktop\MCreator181\.\jdk
C:\Users\igmck\Desktop\MCreator181\forge>gradlew -Dorg.gradle.daemon=false -Dorg.gradle.parallel=false -Dorg.gradle.jvmargs="-Xms625m -Xmx2048m" cleanCache clean setupDecompWorkspace --refresh-dependencies 
This mapping 'snapshot_20171003' was designed for MC 1.12! Use at your own peril.
#################################################
         ForgeGradle 2.3-SNAPSHOT-3996470        
  https://github.com/MinecraftForge/ForgeGradle  
#################################################
                 Powered by MCP                  
             http://modcoderpack.com             
     by: Searge, ProfMobius, R4wk, ZeuX          
     Fesh0r, IngisKahn, bspkrs, LexManos         
#################################################
:cleanCache
:clean FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':clean'.
> Unable to delete directory: C:\Users\igmck\Desktop\MCreator181\forge\build\tmp\recompileMc\compiled\net\minecraft\block
* 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: 19.448 secs
C:\Users\igmck\Desktop\MCreator181\forge>
Task completed with return code 0 in 20461 milliseconds
   
Executing gradle command: cleanCache clean setupDecompWorkspace --refresh-dependencies
Build info: MCreator 1.8.1, 64-bit, 8144 MB, Windows 10 - cmd, JVM 1.8.0_172, JAVA_HOME: C:\Users\igmck\Desktop\MCreator181\.\jdk
C:\Users\igmck\Desktop\MCreator181\forge>gradlew -Dorg.gradle.daemon=false -Dorg.gradle.parallel=false -Dorg.gradle.jvmargs="-Xms625m -Xmx2048m" cleanCache clean setupDecompWorkspace --refresh-dependencies 
This mapping 'snapshot_20171003' was designed for MC 1.12! Use at your own peril.
#################################################
         ForgeGradle 2.3-SNAPSHOT-3996470        
  https://github.com/MinecraftForge/ForgeGradle  
#################################################
                 Powered by MCP                  
             http://modcoderpack.com             
     by: Searge, ProfMobius, R4wk, ZeuX          
     Fesh0r, IngisKahn, bspkrs, LexManos         
#################################################
:cleanCache
:clean FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':clean'.
> Unable to delete directory: C:\Users\igmck\Desktop\MCreator181\forge\build\tmp\recompileMc\compiled\net\minecraftforge\fluids
* 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: 26.009 secs
C:\Users\igmck\Desktop\MCreator181\forge>
Task completed with return code 0 in 26573 milliseconds