There’s an easy fix to the issue:

com/rsa/jsafe/JSAFE_SecureRandom

Cannot serve request to /content/forms/af/formwithattachments/jcr:content/guideContainer.af.submit.jsp in com.adobe.aemds.guide.servlet.GuideSubmitServlet

Exception:

java.lang.NoClassDefFoundError: com/rsa/jsafe/JSAFE_SecureRandom

 

• Make sure AEM isn’t running.
• Open your sling.properties file under \crx-quickstart\conf\ with Brackets or equivalent good editor.
• Add the following properties to the sling.properties file

sling.bootdelegation.class.com.rsa.jsafe.provider.JsafeJCE=com.rsa.*
sling.bootdelegation.class.org.bouncycastle.jce.provider.BouncyCastleProvider=org.bouncycastle.*

• Save and start your server.

Take note that if this step was not taken care of as part of your AEM / Forms installation, you may want to review all of the steps in the configuration guide. It is likely things like PDFg are not setup.