Error downloading http://downloads.arduino.cc/packages/package_index.json java.lang.RuntimeException: java.lang.Exception: Error downloading http://downloads.arduino.cc/packages/package_index.json at cc.arduino.contributions.packages.ui.ContributionManagerUI.lambda$onUpdatePressed$0(ContributionManagerUI.java:151) at java.lang.Thread.run(Thread.java:748) Caused by: java.lang.Exception: Error downloading http://downloads.arduino.cc/packages/package_index.json at cc.arduino.contributions.DownloadableContributionsDownloader.download(DownloadableContributionsDownloader.java:131) at cc.arduino.contributions.packages.ContributionInstaller.download(ContributionInstaller.java:334) at cc.arduino.contributions.packages.ContributionInstaller.downloadIndexAndSignature(ContributionInstaller.java:309) at cc.arduino.contributions.packages.ContributionInstaller.updateIndex(ContributionInstaller.java:287) at cc.arduino.contributions.packages.ui.ContributionManagerUI.lambda$onUpdatePressed$0(ContributionManagerUI.java:147) ... 1 more Caused by: java.lang.NumberFormatException: For input string: "" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) at java.lang.Integer.parseInt(Integer.java:592) at java.lang.Integer.valueOf(Integer.java:766) at cc.arduino.net.CustomProxySelector.manualProxy(CustomProxySelector.java:146) at cc.arduino.net.CustomProxySelector.getProxyFor(CustomProxySelector.java:71) at cc.arduino.utils.network.FileDownloader.downloadFile(FileDownloader.java:153) at cc.arduino.utils.network.FileDownloader.download(FileDownloader.java:128) at cc.arduino.contributions.DownloadableContributionsDownloader.download(DownloadableContributionsDownloader.java:129) ... 5 more