Go back to JDK 17. Looks like bouncycastle jdk18on-1.83 is compatible with JDK17 after all...

Alain Knaff · Alain Knaff · commit 8cd24f007473 · 2026-01-23T21:06:05.000+01:00
diff --git a/app/build.gradle b/app/build.gradle
@@ -27,11 +27,11 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility = JavaVersion.VERSION_18
-        targetCompatibility = JavaVersion.VERSION_18
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
     }
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_18
+        jvmTarget = JavaVersion.VERSION_17
     }
 
     lintOptions {

Original file line number	Diff line number	Diff line change
`@@ -27,11 +27,11 @@ android {`
`27`	`27`	`}`
`28`	`28`	`}`
`29`	`29`	`compileOptions {`
`30`		`- sourceCompatibility = JavaVersion.VERSION_18`
`31`		`- targetCompatibility = JavaVersion.VERSION_18`
	`30`	`+ sourceCompatibility = JavaVersion.VERSION_17`
	`31`	`+ targetCompatibility = JavaVersion.VERSION_17`
`32`	`32`	`}`
`33`	`33`	`kotlinOptions {`
`34`		`- jvmTarget = JavaVersion.VERSION_18`
	`34`	`+ jvmTarget = JavaVersion.VERSION_17`
`35`	`35`	`}`
`36`	`36`
`37`	`37`	`lintOptions {`