I ran the installer and renamed minecraft_server.1.5.2.jar to minecraft_server.jar, which seemed to help, but now I'm getting a different error.
2020-01-15 19:36:14 [INFO] [ForgeModLoader] Forge Mod Loader version 5.2.23.738 for Minecraft 1.5.2 loading
2020-01-15 19:36:14 [INFO] [ForgeModLoader] Java is OpenJDK 64-Bit Server VM, version 1.8.0_232, running on Linux:amd64:4.15.0-74-generic, installed at /usr/lib/jvm/java-8-openjdk-amd64/jre
2020-01-15 19:36:15 [INFO] [ForgeModLoader] Downloading file http://files.minecraftforge.net/fmllibs/bcprov-jdk15on-148.jar
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] There was a problem downloading the file bcprov-jdk15on-148.jar automatically. Perhaps you have an environment without internet access. You will need to download the file manually or restart and let it try again
2020-01-15 19:36:15 [INFO] [ForgeModLoader] Downloading file http://files.minecraftforge.net/fmllibs/scala-library.jar
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] There was a problem downloading the file scala-library.jar automatically. Perhaps you have an environment without internet access. You will need to download the file manually or restart and let it try again
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] There were errors during initial FML setup. Some files failed to download or were otherwise corrupted. You will need to manually obtain the following files from these download links and ensure your lib directory is clean.
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] *** Download http://files.minecraftforge.net/fmllibs/argo-small-3.2.jar
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] *** Download http://files.minecraftforge.net/fmllibs/guava-14.0-rc3.jar
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] *** Download http://files.minecraftforge.net/fmllibs/asm-all-4.1.jar
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] *** Download http://files.minecraftforge.net/fmllibs/bcprov-jdk15on-148.jar
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] *** Download http://files.minecraftforge.net/fmllibs/deobfuscation_data_1.5.2.zip
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] *** Download http://files.minecraftforge.net/fmllibs/scala-library.jar
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] <===========>
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] The following is the errors that caused the setup to fail. They may help you diagnose and resolve the issue
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] A download error occured
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] A download error occured
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] <<< ==== >>>
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] The following is diagnostic information for developers to review.
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] Error details
java.lang.RuntimeException: A download error occured
at cpw.mods.fml.relauncher.RelaunchLibraryManager.downloadFile(RelaunchLibraryManager.java:548)
at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:165)
at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:172)
at cpw.mods.fml.relauncher.FMLRelauncher.relaunchServer(FMLRelauncher.java:147)
at cpw.mods.fml.relauncher.FMLRelauncher.handleServerRelaunch(FMLRelauncher.java:45)
at net.minecraft.server.MinecraftServer.main(MinecraftServer.java:1367)
Caused by: java.io.IOException: Server returned HTTP response code: 500 for URL: http://files.minecraftforge.net/fmllibs/bcprov-jdk15on-148.jar
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1950)
at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1945)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:1944)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1514)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498)
at cpw.mods.fml.relauncher.RelaunchLibraryManager.downloadFile(RelaunchLibraryManager.java:532)
... 5 more
Caused by: java.io.IOException: Server returned HTTP response code: 500 for URL: http://files.minecraftforge.net/fmllibs/bcprov-jdk15on-148.jar
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1900)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498)
at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:3061)
at java.net.URLConnection.getHeaderFieldLong(URLConnection.java:629)
at java.net.URLConnection.getContentLengthLong(URLConnection.java:501)
at java.net.URLConnection.getContentLength(URLConnection.java:485)
at cpw.mods.fml.relauncher.RelaunchLibraryManager.downloadFile(RelaunchLibraryManager.java:531)
... 5 more
2020-01-15 19:36:15 [SEVERE] [ForgeModLoader] Error details
java.lang.RuntimeException: A download error occured
at cpw.mods.fml.relauncher.RelaunchLibraryManager.downloadFile(RelaunchLibraryManager.java:548)
at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:165)
at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:172)
at cpw.mods.fml.relauncher.FMLRelauncher.relaunchServer(FMLRelauncher.java:147)
at cpw.mods.fml.relauncher.FMLRelauncher.handleServerRelaunch(FMLRelauncher.java:45)
at net.minecraft.server.MinecraftServer.main(MinecraftServer.java:1367)
Caused by: java.io.IOException: Server returned HTTP response code: 500 for URL: http://files.minecraftforge.net/fmllibs/scala-library.jar
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1950)
at sun.net.www.protocol.http.HttpURLConnection$10.run(HttpURLConnection.java:1945)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:1944)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1514)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498)
at cpw.mods.fml.relauncher.RelaunchLibraryManager.downloadFile(RelaunchLibraryManager.java:532)
... 5 more
Caused by: java.io.IOException: Server returned HTTP response code: 500 for URL: http://files.minecraftforge.net/fmllibs/scala-library.jar
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1900)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498)
at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLConnection.java:3061)
at java.net.URLConnection.getHeaderFieldLong(URLConnection.java:629)
at java.net.URLConnection.getContentLengthLong(URLConnection.java:501)
at java.net.URLConnection.getContentLength(URLConnection.java:485)
at cpw.mods.fml.relauncher.RelaunchLibraryManager.downloadFile(RelaunchLibraryManager.java:531)
... 5 more
2020-01-15 19:36:15 [INFO] [STDERR] Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: A fatal error occured and FML cannot continue
2020-01-15 19:36:15 [INFO] [STDERR] at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:192)
2020-01-15 19:36:15 [INFO] [STDERR] at cpw.mods.fml.relauncher.FMLRelauncher.relaunchServer(FMLRelauncher.java:147)
2020-01-15 19:36:15 [INFO] [STDERR] at cpw.mods.fml.relauncher.FMLRelauncher.handleServerRelaunch(FMLRelauncher.java:45)
2020-01-15 19:36:15 [INFO] [STDERR] at net.minecraft.server.MinecraftServer.main(MinecraftServer.java:1367)
2020-01-15 19:36:15 [INFO] [STDERR] Caused by: java.lang.RuntimeException: A fatal error occured and FML cannot continue
2020-01-15 19:36:15 [INFO] [STDERR] at cpw.mods.fml.relauncher.RelaunchLibraryManager.handleLaunch(RelaunchLibraryManager.java:261)
2020-01-15 19:36:15 [INFO] [STDERR] at cpw.mods.fml.relauncher.FMLRelauncher.setupHome(FMLRelauncher.java:172)
2020-01-15 19:36:15 [INFO] [STDERR] ... 3 more