In reply to @emilazy:matrix.org
source is very likely to get archived or have another source, random mystery meat .jars are bad for supply-chain security and bad for longevity

the actual Gradle fixes were trivial

diff --git a/build.gradle b/build.gradle
index 8fd6d27a49..20c6c2461c 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,16 +1,14 @@
 buildscript {
     repositories {
-        jcenter()
+        mavenCentral()
     }
     dependencies {
-        classpath 'edu.sc.seis.gradle:launch4j:2.4.4'
         classpath 'net.sf.proguard:proguard-gradle:6.1.0'
     }
 }
 
 apply plugin: 'java'
 apply plugin: 'distribution'
-apply plugin: 'edu.sc.seis.launch4j'
 
 // Common configuration //
 rootProject.version='1.6.6'
@@ -29,7 +27,7 @@
     }
 
     repositories {
-        jcenter()
+        mavenCentral()
     }
 
     configurations {
@@ -105,16 +103,3 @@
     libraryjars System.getProperty('java.home') + '/lib/rt.jar'
     libraryjars System.getProperty('java.home') + '/jmods/'
 }
-
-// Java executable wrapper for Windows //
-launch4j {
-    createExe.dependsOn 'proguard'
-
-    version = textVersion = project.version
-    fileDescription = productName = 'JD-GUI'
-    errTitle 'JD-GUI Windows Wrapper'
-    copyright 'JD-GUI (C) 2008-2019 Emmanuel Dupuy'
-    icon projectDir.path + '/src/launch4j/resources/images/jd-gui.ico'
-    jar projectDir.path + '/' + proguard.outJarFiles[0]
-    bundledJrePath = '%JAVA_HOME%'
-}