I recently tried to install forge on my mac and got this error on my log.
JVM info: Oracle Corporation - 1.8.0_261 - 25.261-b12
java.net.preferIPv4Stack=true
Found java version 1.8.0_261
Extracting json
Considering minecraft client jar
Downloading libraries
Considering library net.minecraftforge:forge:1.16.2-33.0.20
File exists: Checksum validated.
Considering library org.ow2.asm:asm:7.2
File exists: Checksum validated.
Considering library org.ow2.asm:asm-commons:7.2
File exists: Checksum validated.
Considering library org.ow2.asm:asm-tree:7.2
File exists: Checksum validated.
Considering library org.ow2.asm:asm-util:7.2
File exists: Checksum validated.
Considering library org.ow2.asm:asm-analysis:7.2
File exists: Checksum validated.
Considering library cpw.mods:modlauncher:6.1.1
File exists: Checksum validated.
Considering library cpw.mods:grossjava9hacks:1.3.0
File exists: Checksum validated.
Considering library net.minecraftforge:accesstransformers:2.2.0-shadowed
File exists: Checksum validated.
Considering library net.minecraftforge:eventbus:3.0.3-service
File exists: Checksum validated.
Considering library net.minecraftforge:forgespi:3.1.1
File exists: Checksum validated.
Considering library net.minecraftforge:coremods:3.0.0
File exists: Checksum validated.
Considering library net.minecraftforge:unsafe:0.2.0
File exists: Checksum validated.
Considering library com.electronwill.night-config:core:3.6.2
File exists: Checksum validated.
Considering library com.electronwill.night-config:toml:3.6.2
File exists: Checksum validated.
Considering library org.jline:jline:3.12.1
File exists: Checksum validated.
Considering library org.apache.maven:maven-artifact:3.6.0
File exists: Checksum validated.
Considering library net.jodah:typetools:0.8.1
File exists: Checksum validated.
Considering library org.apache.logging.log4j:log4j-api:2.11.2
File exists: Checksum validated.
Considering library org.apache.logging.log4j:log4j-core:2.11.2
File exists: Checksum validated.
Considering library net.minecrell:terminalconsoleappender:1.2.0
File exists: Checksum validated.
Considering library net.sf.jopt-simple:jopt-simple:5.0.4
File exists: Checksum validated.
Considering library org.spongepowered:mixin:0.8
File exists: Checksum validated.
Considering library com.github.jponge:lzma-java:1.3
Downloading library from https://files.minecraftforge.net/maven/com/github/jponge/lzma-java/1.3/lzma-java-1.3.jar
Exception in thread "main"
java.lang.ExceptionInInitializerError
at javax.crypto.Cipher.getInstance(Cipher.java:518)
at sun.security.ssl.JsseJce.getCipher(JsseJce.java:189)
at sun.security.ssl.SSLCipher.isTransformationAvailable(SSLCipher.java:483)
at sun.security.ssl.SSLCipher.<init>(SSLCipher.java:472)
at sun.security.ssl.SSLCipher.<clinit>(SSLCipher.java:81)
at sun.security.ssl.CipherSuite.<clinit>(CipherSuite.java:67)
at sun.security.ssl.SSLContextImpl.getApplicableSupportedCipherSuites(SSLContextImpl.java:345)
at sun.security.ssl.SSLContextImpl.access$100(SSLContextImpl.java:46)
at sun.security.ssl.SSLContextImpl$AbstractTLSContext.<clinit>(SSLContextImpl.java:577)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at java.security.Provider$Service.getImplClass(Provider.java:1701)
at java.security.Provider$Service.newInstance(Provider.java:1659)
at sun.security.jca.GetInstance.getInstance(GetInstance.java:236)
at sun.security.jca.GetInstance.getInstance(GetInstance.java:164)
at javax.net.ssl.SSLContext.getInstance(SSLContext.java:156)
at javax.net.ssl.SSLContext.getDefault(SSLContext.java:96)
at javax.net.ssl.SSLSocketFactory.getDefault(SSLSocketFactory.java:122)
at javax.net.ssl.HttpsURLConnection.getDefaultSSLSocketFactory(HttpsURLConnection.java:332)
at javax.net.ssl.HttpsURLConnection.<init>(HttpsURLConnection.java:289)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.<init>(HttpsURLConnectionImpl.java:99)
at sun.net.www.protocol.https.Handler.openConnection(Handler.java:62)
at sun.net.www.protocol.https.Handler.openConnection(Handler.java:57)
at java.net.URL.openConnection(URL.java:1001)
at net.minecraftforge.installer.DownloadUtils.getConnection(DownloadUtils.java:197)
at net.minecraftforge.installer.DownloadUtils.download(DownloadUtils.java:144)
at net.minecraftforge.installer.DownloadUtils.download(DownloadUtils.java:134)
at net.minecraftforge.installer.DownloadUtils.downloadLibrary(DownloadUtils.java:123)
at net.minecraftforge.installer.actions.Action.downloadLibraries(Action.java:79)
at net.minecraftforge.installer.actions.ClientInstall.run(ClientInstall.java:108)
at net.minecraftforge.installer.InstallerPanel.run(InstallerPanel.java:428)
at net.minecraftforge.installer.SimpleInstaller.launchGui(SimpleInstaller.java:170)
at net.minecraftforge.installer.SimpleInstaller.main(SimpleInstaller.java:143)
Caused by: java.lang.SecurityException: Can not initialize cryptographic mechanism
at javax.crypto.JceSecurity.<clinit>(JceSecurity.java:93)
... 33 more
Caused by: java.lang.SecurityException: The jurisdiction policy files are not signed by the expected signer! (Policy files are specific per major JDK release.Ensure the correct version is installed.)
at javax.crypto.JarVerifier.verifyPolicySigned(JarVerifier.java:336)
at javax.crypto.JceSecurity.loadPolicies(JceSecurity.java:378)
at javax.crypto.JceSecurity.setupJurisdictionPolicies(JceSecurity.java:323)
at javax.crypto.JceSecurity.access$000(JceSecurity.java:50)
at javax.crypto.JceSecurity$1.run(JceSecurity.java:85)
at java.security.AccessController.doPrivileged(Native Method)
at javax.crypto.JceSecurity.<clinit>(JceSecurity.java:82)
... 33 more