Errors in build.xml

[P5music]

I changed the os of my development machine to

System:    Kernel: 5.4.0-72-generic x86_64 bits: 64 compiler: gcc v: 9.3.0 Desktop: MATE 1.24.0

I installed IntelliJ Idea, then my project, CodenameOne plugin, JDK, the cef folder inside .codenameone and so on.

IntelliJ IDEA 2021.1 (Community Edition)
Build #IC-211.6693.111, built on April 6, 2021
Runtime version: 11.0.10+9-b1341.35 amd64
VM: Dynamic Code Evolution 64-Bit Server VM by JetBrains s.r.o.
Linux 5.4.0-72-generic
GC: G1 Young Generation, G1 Old Generation
Memory: 982M
Cores: 4
Non-Bundled Plugins: com.codename1.plugin.intellij (7.03)
Kotlin: 211-1.4.32-release-IJ6693.72

Current Desktop: MATE

When running now I get

/home/pc/.jdks/corretto-1.8.0_292/bin/java -Xms128m -Xmx981m -XX:ReservedCodeCacheSize=512m -XX:+UseG1GC -XX:SoftRefLRUPolicyMSPerMB=50 -XX:CICompilerCount=2 -XX:+HeapDumpOnOutOfMemoryError -XX:-OmitStackTraceInFastThrow -ea -Dsun.io.useCanonCaches=false -Djdk.http.auth.tunneling.disabledSchemes=\"\" -Djdk.attach.allowAttachSelf=true -Djdk.module.illegalAccess.silent=true -Dkotlinx.coroutines.debug=off -Dsun.tools.attach.tmp.only=true -Dsun.awt.disablegrab=true -javaagent:/home/pc/sviluppo/idea-IC-211.6693.111/lib/idea_rt.jar=43325:/home/pc/sviluppo/idea-IC-211.6693.111/bin -Dfile.encoding=UTF-8 -classpath /home/pc/sviluppo/myapp_cp/out/production/myapp_cp:/home/pc/sviluppo/myapp_cp/src:/home/pc/sviluppo/myapp_cp/lib/CodenameOne.jar:/home/pc/sviluppo/myapp_cp/JavaSE.jar:native/internal_tmp:lib/impl/cls com.codename1.impl.javase.Simulator com.myapp.app.myapp

Adding CEF to classpath
java.lang.ClassNotFoundException: com.myapp.app.myapp

Ant inspection says:
Failed to load type(s):
Resource "proguard/ant/task.properties" not found in the classpath

I see that the build file has errors, something is in red, like:
Property 'selectedOfflineBuilder' is unknown
Property 'selectedOfflineBuilder' is unknown
Property 'selectedOfflineBuilder' is unknown
Property 'toString:first' is unknown
Property 'codename1.desktop.mac.certificate' is unknown
Property 'codename1.desktop.mac.certificatePassword' is unknown
Property 'codename1.windows.certificate' is unknown
Property 'codename1.windows.certificatePassword' is unknown

It seems to have to do with CodenameOne plugin, but also the CN1lib refresh was done. If performed again I get

/home/pc/sviluppo/myapp_cp/nbproject/build-impl.xml:1007: Manifest file: /home/pc/sviluppo/myapp_cp/build/null428155819 does not exist.
    at org.apache.tools.ant.taskdefs.Jar.setManifest(Jar.java:302)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tools.ant.IntrospectionHelper$7.set(IntrospectionHelper.java:1093)
    at org.apache.tools.ant.IntrospectionHelper$AttributeSetter.setObject(IntrospectionHelper.java:1492)
    at org.apache.tools.ant.IntrospectionHelper.setAttribute(IntrospectionHelper.java:406)
    at org.apache.tools.ant.RuntimeConfigurable.maybeConfigure(RuntimeConfigurable.java:527)
    at org.apache.tools.ant.RuntimeConfigurable.maybeConfigure(RuntimeConfigurable.java:463)
    at org.apache.tools.ant.Task.maybeConfigure(Task.java:203)
    at org.apache.tools.ant.UnknownElement.configure(UnknownElement.java:201)
    at org.apache.tools.ant.UnknownElement.maybeConfigure(UnknownElement.java:165)
    at org.apache.tools.ant.Task.perform(Task.java:349)
    at org.apache.tools.ant.Target.execute(Target.java:449)
    at org.apache.tools.ant.Target.performTasks(Target.java:470)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1388)
    at org.apache.tools.ant.Project.executeTarget(Project.java:1361)
    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1251)
    at org.apache.tools.ant.Main.runBuild(Main.java:834)
    at org.apache.tools.ant.Main.startAnt(Main.java:223)
    at org.apache.tools.ant.Main.start(Main.java:190)
    at org.apache.tools.ant.Main.main(Main.java:274)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.ant.execution.AntMain2.main(AntMain2.java:31)

Thanks in advance

[Shai Almog]

In which IDE did you initially generate the project?
I would suggest using the maven migration tool which might be simpler than going down the rabbit hole of what broke in the migration.