Q: How can I unsign an existing jar file? A: Follow the steps below to remove a signature from a jar file Open the jar using WinRar or Winzip (jars are actually zip files) Go into the META-INF directory Delete all files (*.SF, *.RSA) but keep MANIFEST-MF. Open the MANIFEST.MF and Remove all entries below […]
Adobe Reader DC displays weird characters for embedded fonts when zooming
We found today a weird issue in the way Adobe Reader DC and Adobe Acrobat render some embedded fonts at certain zoom level. We first thought this was an Adobe bug but looking further into this issue, we found out that it was an issue with bitmap font tables being preserved by jWordConvert when subsetting […]
How to resolve Firefox “Java Plugin has Crashed” Error when running applets
If you see this error when trying to run an applet in Firefox: most probably this issue is due to Firefox blocking the Java plugin because it is “outdated”. To resolve this, try the following: Update your Java Plugin to the latest version Update Firefox to the latest version Then restart Firefox and try again! […]
Applets: IE11 not seeing the latest version of Java and redirecting to Oracle
Q: We are currently upgrading all machines to IE11 and JRE 8 u66. Even though we have the latest version of Java, when we select a document to annotate it is redirecting to the Oracle home page. A: Sometimes, even after installing the latest version of Java, it will still not be recognized in Internet […]
How to Resolve Applet ClassNotFoundException – Handshake Failure – HTTPS – New Issue with Java 8 Latest Build
After a recent Java 8 update, our applets started giving us a ClassNotFoundException as though they could not find the main jar for the applet in the classpath (when it is actually present). This is what we find in the Java Console: java.lang.ClassNotFoundException: qoppa.webNotes.PDFWebNotes at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown […]
How can I run Java Applets in Chrome Browser?
Chrome on Mac and Windows To run Java applets on Mac and Windows in Chrome, one has to enable NPAPI starting with Chrome Version 42 and later. Enabling NPAPI As of Chrome Version 42, an additional configuration step is required to continue using NPAPI plugins. In your URL bar, enter: chrome://flags/#enable-npapi Click the Enable link for the Enable […]
Caching applets on client computers
Q: When running one of Qoppa’s PDF library or component within an applet, can the java applet be configured to be cached on the client’s PC to improve loading time? A: The applet does cache on the client computer, this is controlled by Java and the Java control panel. After launching the first time, the […]
“Insufficient data for an image” in latest version of Adobe Reader
Note that the latest versions of Adobe Reader / Acrobat 10.1.4 and 9.5.2 have a known issue and users may encounter the following error when opening PDF documents in Adobe’s latest versions of the viewers: “Insufficient data for an image” http://blogs.adobe.com/dmcmahon/2012/08/21/acrobat-insufficient-data-for-an-image-error-after-updating-to-10-1-4-or-9-5-2/Update: This issue has been fixed with the latest version of Reader XI. Adobe is […]
How to add the new Manifest entries to jar files required when running applets
What are the new manifest entries required for applets? Java 1.7 has recently added new security requirements when running applets. Java now requires additional entries in the manifest files of the jars that the applet use. If these entries are not present, Java will show warning dialogs raising security concerns. Starting with Java 1.7 update […]
New applets requirements with Java 7 Update 51!
This new release changes the deployment requirements for Applet & Web Start applications with two new requirements: Use of the Permissions Manifest attribute. Read more about setting the new manifest entries. Valid code signatures. Read more about signing jars and getting an affordable code signing certificate. Read more about these new security requirements in Java 7 update 51.