Apk signer entry does not contain a key

Question

I am trying to sign an APK manually using APK signer using this code

apksigner sign --ks D:\Android\SDK\keystores\release.keystore --ks-key-alias uploadcertificate --out app-release.apk app.apk

but it's giving me an error saying that

Failed to load signer "signer #1": D:\Android\SDK\keystores\release.keystore entry "uploadcertificate" does not contain a key

however, when I use keytool to list the aliases in my keystore, I am able to see the alias uploadcertificate.

keytool -v -list -keystore D:\Android\SDK\Keystores\release.keystore
Enter keystore password:
Keystore type: JKS
Keystore provider: SUN

Your keystore contains 1 entry

Alias name: uploadcertificate
Creation date: May 21, 2018
Entry type: trustedCertEntry

Owner: C=US, O=Android, CN=Android Debug
Issuer: C=US, O=Android, CN=Android Debug
Serial number: 1
Valid from: Mon Feb 13 23:47:57 IST 2017 until: Wed Feb 06 23:47:57 IST 2047
Certificate fingerprints:
        MD5:  **:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**
        SHA1: **:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**
        SHA256: **:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**:**
Signature algorithm name: SHA1withRSA
Subject Public Key Algorithm: 1024-bit RSA key
Version: 1

Any Idea Why this might be happening?

Answer 1

Please check Keystore complete file name and make sure that you use same .keystore file which you uploaded in secure file (in Library) that you used alias,passwords.

Answer 2

When generating your Keystore, do not use any illegal characters, especially in your password. I had "#" in my password. Generatin new key with just letters and numbers allowed me to sign the app.

More explanation/answer found here: Visual Studio's AndroidApkSigner does not find key in keystore