Android Question b4a error debug

Hello everyone. i just downloaded all b4a again after a long time, following erel's tutorial to the letter.
at the first test debug I get this:

I sign the package file (private key). Error
Could not load signer "signer # 1"
java.io.FileNotFoundException: cc (Cannot find the specified file)
on java.base / java.io.FileInputStream.open0 (native method)
on java.base / java.io.FileInputStream.open (FileInputStream.java:219)
on java.base / java.io.FileInputStream. <init> (FileInputStream.java:157)
on java.base / java.io.FileInputStream. <init> (FileInputStream.java:112)
on com.android.apksigner.SignerParams.loadKeyStoreFromFile (SignerParams.java:352)
on com.android.apksigner.SignerParams.loadPrivateKeyAndCertsFromKeyStore (SignerParams.java:239)
on com.android.apksigner.SignerParams.loadPrivateKeyAndCerts (SignerParams.java:181)
on com.android.apksigner.ApkSignerTool.getSignerConfig (ApkSignerTool.java:368)
on com.android.apksigner.ApkSignerTool.sign (ApkSignerTool.java:291)
on com.android.apksigner.ApkSignerTool.main (ApkSignerTool.java:84)

I don't understand what it means and where to solve the problem. can anyone help me?