Emulator crashes with error code: Error from Companion: java.lang.RuntimeException: invalid syntax in eval form: :10:1

Error from Companion: java.lang.RuntimeException: invalid syntax in eval form: :10:1: caught exception in inliner for # - java.lang.RuntimeException: no such class: com.google.appinventor.components.runtime.com.google.appinventor.components.runtime.Switch gnu.bytecode.ObjectType.getReflectClass(ObjectType.java:148) gnu.bytecode.ClassType.getModifiers(ClassType.java:103) gnu.bytecode.ClassType.isInterface(ClassType.java:471) gnu.expr.InlineCalls.checkType(InlineCalls.java:56) gnu.expr.InlineCalls.visit(InlineCalls.java:49) gnu.expr.InlineCalls.visitSetExpValue(InlineCalls.java:363) gnu.expr.InlineCalls.visitSetExpValue(InlineCalls.java:28) gnu.expr.ExpVisitor.visitSetExp(ExpVisitor.java:114) gnu.expr.InlineCalls.visitSetExp(InlineCalls.java:369) gnu.expr.InlineCalls.visitSetExp(InlineCalls.java:28) gnu.expr.SetExp.visit(SetExp.java:406) gnu.expr.ExpVisitor.visit(ExpVisitor.java:55) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.visitBeginExp(InlineCalls.java:272) gnu.expr.InlineCalls.visitBeginExp(InlineCalls.java:28) gnu.expr.BeginExp.visit(BeginExp.java:156) gnu.expr.ExpVisitor.visit(ExpVisitor.java:51) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.visitBeginExp(InlineCalls.java:272) gnu.expr.InlineCalls.visitBeginExp(InlineCalls.java:28) gnu.expr.BeginExp.visit(BeginExp.java:156) gnu.expr.ExpVisitor.visit(ExpVisitor.java:51) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.visitLetExp(InlineCalls.java:317) gnu.expr.InlineCalls.visitLetExp(InlineCalls.java:28) gnu.expr.LetExp.visit(LetExp.java:207) gnu.expr.ExpVisitor.visit(ExpVisitor.java:51) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.visit(InlineCalls.java:28) gnu.expr.LambdaExp.visitChildrenOnly(LambdaExp.java:1664) gnu.expr.LambdaExp.visitChildren(LambdaExp.java:1651) gnu.expr.InlineCalls.visitScopeExp(InlineCalls.java:279) gnu.expr.InlineCalls.visitLambdaExp(InlineCalls.java:349) gnu.expr.InlineCalls.visitLambdaExp(InlineCalls.java:28) gnu.expr.LambdaExp.visit(LambdaExp.java:1640) gnu.expr.ExpVisitor.visit(ExpVisitor.java:55) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.visit(InlineCalls.java:28) gnu.expr.ExpVisitor.visitAndUpdate(ExpVisitor.java:162) gnu.expr.ExpVisitor.visitExps(ExpVisitor.java:176) gnu.expr.ApplyExp.visitArgs(ApplyExp.java:416) gnu.kawa.reflect.CompileInvoke.validateApplyInvoke(CompileInvoke.java:23) java.lang.reflect.Method.invokeNative(Native Method) java.lang.reflect.Method.invoke(Method.java:521) gnu.expr.InlineCalls.maybeInline(InlineCalls.java:467) gnu.expr.QuoteExp.validateApply(QuoteExp.java:150) gnu.expr.ReferenceExp.validateApply(ReferenceExp.java:191) gnu.kawa.functions.CompilationHelpers.validateApplyToArgs(CompilationHelpers.java:66) java.lang.reflect.Method.invokeNative(Native Method) java.lang.reflect.Method.invoke(Method.java:521) gnu.expr.InlineCalls.maybeInline(InlineCalls.java:467) gnu.expr.QuoteExp.validateApply(QuoteExp.java:150) gnu.expr.ReferenceExp.validateApply(ReferenceExp.java:191) gnu.expr.InlineCalls.visitApplyExp(InlineCalls.java:119) gnu.expr.InlineCalls.visitApplyExp(InlineCalls.java:28) gnu.expr.ApplyExp.visit(ApplyExp.java:411) gnu.expr.ExpVisitor.visit(ExpVisitor.java:55) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.QuoteExp.validateApply(QuoteExp.java:162) gnu.expr.ReferenceExp.validateApply(ReferenceExp.java:191) gnu.kawa.functions.CompilationHelpers.validateApplyToArgs(CompilationHelpers.java:66) java.lang.reflect.Method.invokeNative(Native Method) java.lang.reflect.Method.invoke(Method.java:521) gnu.expr.InlineCalls.maybeInline(InlineCalls.java:467) gnu.expr.QuoteExp.validateApply(QuoteExp.java:150) gnu.expr.ReferenceExp.validateApply(ReferenceExp.java:191) gnu.expr.InlineCalls.visitApplyExp(InlineCalls.java:119) gnu.expr.InlineCalls.visitApplyExp(InlineCalls.java:28) gnu.expr.ApplyExp.visit(ApplyExp.java:411) gnu.expr.ExpVisitor.visit(ExpVisitor.java:51) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.visitBeginExp(InlineCalls.java:272) gnu.expr.InlineCalls.visitBeginExp(InlineCalls.java:28) gnu.expr.BeginExp.visit(BeginExp.java:156) gnu.expr.ExpVisitor.visit(ExpVisitor.java:51) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.visit(InlineCalls.java:28) gnu.expr.LambdaExp.visitChildrenOnly(LambdaExp.java:1664) gnu.expr.LambdaExp.visitChildren(LambdaExp.java:1651) gnu.expr.InlineCalls.visitScopeExp(InlineCalls.java:279) gnu.expr.InlineCalls.visitLambdaExp(InlineCalls.java:349) gnu.expr.InlineCalls.visitLambdaExp(InlineCalls.java:28) gnu.expr.ExpVisitor.visitModuleExp(ExpVisitor.java:103) gnu.expr.ModuleExp.visit(ModuleExp.java:482) gnu.expr.ExpVisitor.visit(ExpVisitor.java:51) gnu.expr.InlineCalls.visit(InlineCalls.java:46) gnu.expr.InlineCalls.inlineCalls(InlineCalls.java:33) gnu.expr.Compilation.walkModule(Compilation.java:994) gnu.expr.Compilation.process(Compilation.java:1965) gnu.expr.ModuleInfo.loadByStages(ModuleInfo.java:330) gnu.expr.ModuleExp.evalModule1(ModuleExp.java:238) gnu.expr.ModuleExp.evalModule(ModuleExp.java:198) gnu.expr.Language.eval(Language.java:943) gnu.expr.Language.eval(Language.java:883) gnu.expr.Language.eval(Language.java:865) com.google.appinventor.components.runtime.util.AppInvHTTPD.serve(AppInvHTTPD.java:188) com.google.appinventor.components.runtime.util.NanoHTTPD$HTTPSession.run(NanoHTTPD.java:470) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561) java.lang.Thread.run(Thread.java:1096)

Have you updated companion to the latest version? Also show the blocks that cause this error. Is the error for the android or ios version?

You need version 2.67 or 2.67u now.

Sincere apologies. I just wanted to understand the basics of app development.
I am a open source/freeware enthusiast (because I don't have much money) and a compulsive DIYer (for the same reason :slight_smile: ).
I am running this on debian 11 bullseye, developing for android and none of the code blocks show any warning/errors. When I run emulator everything goes fine until the emulator shows the MIT app inventor screen....and then emulator screen goes blank besides the error page displayed on the MIT app developer page.