hello, i am also giving forge error, i can't open it pls help me

[wedsda]

Considering library net.minecraftforge:forge:1.11.2-13.20.1.2588: Not Downloading {Wrong Side}
Considering library net.minecraft:launchwrapper:1.12: Not Downloading {Wrong Side}
Considering library org.ow2.asm:asm-all:5.0.3: Not Downloading {Wrong Side}
Considering library jline:jline:2.13: Not Downloading {Wrong Side}
Considering library com.typesafe.akka:akka-actor_2.11:2.3.3
Considering library com.typesafe:config:1.2.1
Considering library org.scala-lang:scala-actors-migration_2.11:1.1.0
Considering library org.scala-lang:scala-compiler:2.11.1
Considering library org.scala-lang.plugins:scala-continuations-library_2.11:1.0.2
Checking "C:\Users\yahya\AppData\Roaming\.minecraft\libraries\org\scala-lang\plugins\scala-continuations-library_2.11\1.0.2\scala-continuations-library_2.11-1.0.2.jar" internal checksums
    checksums.sha1 was not found, validation failed
Downloading library org.scala-lang.plugins:scala-continuations-library_2.11:1.0.2
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.Alerts.getSSLException(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(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 sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
    at net.minecraftforge.installer.DownloadUtils$URLISSupplier.getInput(DownloadUtils.java:457)
    at net.minecraftforge.installer.DownloadUtils$URLISSupplier.getInput(DownloadUtils.java:445)
    at com.google.common.io.ByteStreams$6.openStream(ByteStreams.java:989)
    at com.google.common.io.ByteSource.copyTo(ByteSource.java:202)
    at com.google.common.io.Files.copy(Files.java:382)
    at net.minecraftforge.installer.DownloadUtils.downloadFile(DownloadUtils.java:375)
    at net.minecraftforge.installer.DownloadUtils.downloadInstalledLibraries(DownloadUtils.java:64)
    at net.minecraftforge.installer.ClientInstall.run(ClientInstall.java:131)
    at net.minecraftforge.installer.InstallerAction.run(InstallerAction.java:43)
    at net.minecraftforge.installer.InstallerPanel.run(InstallerPanel.java:406)
    at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:165)
    at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:51)
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
Trying unpacked library org.scala-lang.plugins:scala-continuations-library_2.11:1.0.2
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.Alerts.getSSLException(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(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 sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
    at net.minecraftforge.installer.DownloadUtils$URLISSupplier.getInput(DownloadUtils.java:457)
    at net.minecraftforge.installer.DownloadUtils$URLISSupplier.getInput(DownloadUtils.java:445)
    at com.google.common.io.ByteStreams$6.openStream(ByteStreams.java:989)
    at com.google.common.io.ByteSource.copyTo(ByteSource.java:202)
    at com.google.common.io.Files.copy(Files.java:382)
    at net.minecraftforge.installer.DownloadUtils.downloadFile(DownloadUtils.java:375)
    at net.minecraftforge.installer.DownloadUtils.downloadInstalledLibraries(DownloadUtils.java:67)
    at net.minecraftforge.installer.ClientInstall.run(ClientInstall.java:131)
    at net.minecraftforge.installer.InstallerAction.run(InstallerAction.java:43)
    at net.minecraftforge.installer.InstallerPanel.run(InstallerPanel.java:406)
    at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:165)
    at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:51)
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
File not found in installer archive: /maven/org/scala-lang/plugins/scala-continuations-library_2.11/1.0.2/scala-continuations-library_2.11-1.0.2.jar
Considering library org.scala-lang.plugins:scala-continuations-plugin_2.11.1:1.0.2
Considering library org.scala-lang:scala-library:2.11.1
Considering library org.scala-lang:scala-parser-combinators_2.11:1.0.1
Considering library org.scala-lang:scala-reflect:2.11.1
Considering library org.scala-lang:scala-swing_2.11:1.0.1
Considering library org.scala-lang:scala-xml_2.11:1.0.2
Considering library lzma:lzma:0.0.1: Not Downloading {Wrong Side}
Considering library net.sf.jopt-simple:jopt-simple:4.6: Not Downloading {Wrong Side}
Considering library java3d:vecmath:1.5.2
Considering library net.sf.trove4j:trove4j:3.0.3