FORGE NOT INSTALL PLEASE HELP ME

[SAJAL]

JVM info: Oracle Corporation - 1.8.0_341 - 25.341-b10
java.net.preferIPv4Stack=true
Found java version 1.8.0_341
Extracting json
Considering minecraft client jar
javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.ssl.Alert.createSSLException(Unknown Source)
    at sun.security.ssl.TransportContext.fatal(Unknown Source)
    at sun.security.ssl.TransportContext.fatal(Unknown Source)
    at sun.security.ssl.TransportContext.fatal(Unknown Source)
    at sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(Unknown Source)
    at sun.security.ssl.CertificateMessage$T12CertificateConsumer.onCertificate(Unknown Source)
    at sun.security.ssl.CertificateMessage$T12CertificateConsumer.consume(Unknown Source)
    at sun.security.ssl.SSLHandshake.consume(Unknown Source)
    at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
    at sun.security.ssl.HandshakeContext.dispatch(Unknown Source)
    at sun.security.ssl.TransportContext.dispatch(Unknown Source)
    at sun.security.ssl.SSLTransport.decode(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.decode(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readHandshakeRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at java.net.HttpURLConnection.getResponseCode(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(Unknown Source)
    at net.minecraftforge.installer.DownloadUtils.getConnection(DownloadUtils.java:243)
    at net.minecraftforge.installer.DownloadUtils.downloadManifest(DownloadUtils.java:307)
    at net.minecraftforge.installer.json.Util.getVanillaVersion(Util.java:73)
    at net.minecraftforge.installer.actions.ClientInstall.run(ClientInstall.java:89)
    at net.minecraftforge.installer.InstallerPanel.run(InstallerPanel.java:423)
    at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:175)
    at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:147)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(Unknown Source)
    at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
    at sun.security.validator.Validator.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
    ... 25 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
    at java.security.cert.CertPathBuilder.build(Unknown Source)
    ... 31 more
Failed to download version manifest, can not find client jar URL.