Is a Gradle file affected when you add new files - github

Question

On Github while working with my friend on some code (actually experimental malware for pentesting), we set up a Gradle check, and it failed. When it ran, it said this:
FAILURE: Build failed with an exception.
* What went wrong:
A problem occurred configuring root project 'wurstplus-two'.
> Could not resolve all artifacts for configuration ':classpath'.
> Could not resolve net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT.
Required by:
project :
> Could not resolve net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT.
> Unable to load Maven meta-data from http://repo.spongepowered.org/maven/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/maven-metadata.xml.
> Could not get resource 'http://repo.spongepowered.org/maven/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/maven-metadata.xml'.
> Could not GET 'http://repo.spongepowered.org/maven/net/minecraftforge/gradle/ForgeGradle/2.3-SNAPSHOT/maven-metadata.xml'. Received status code 520 from server: Origin Error
> Could not resolve org.spongepowered:mixingradle:0.4-SNAPSHOT.
Required by:
project :
> Skipped due to earlier error
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
BUILD FAILED in 11s
Error: Process completed with exit code 1.
I know we added some files, so I was thinking that might be what happened. I don't know any Gradle, so that's really why I'm asking.
There's actually 2 questions: What does "exit code 1" mean, and was it triggered by those new files being added? The Github repository is here: https://github.com/Scottw1e/wurstplus-two.

Answer 1

try replacing http://repo.spongepowered.org/maven/ with https://repo.spongepowered.org/maven/ in your build.gradle file