RS if corrupt certificate template is uploaded

Log msg: **RedScreen** MALFORMED[1] ::_::			ffo_main_null		org.olat.core.gui.components.form.flexible.impl.FormWrapperContainer		n/a					org.olat.core.gui.components.form.flexible.impl.FormEvent			ONCHANGE			com:ONCHANGE,org.olat.core.gui.components.form.flexible.impl.FormEvent@a30cee6e						org.olat.course.certificate.ui.CertificateChooserController		org.olat.course.certificate.ui.CertificatesOptionsController		org.olat.course.config.ui.CourseSettingsController		org.olat.course.run.CourseRuntimeController		org.olat.core.commons.fullWebApp.BaseFullWebappController	 ::_::
Cause: 

stack of 1.cause::org.olat.core.logging.OLATRuntimeException: MALFORMED[1] -> 
at org.olat.core.gui.exception.ExceptionWindowController.(ExceptionWindowController.java:116)
at org.olat.core.gui.exception.MsgFactory.createMessageChiefController(MsgFactory.java:57)
at org.olat.core.gui.exception.MsgFactory.createMessageChiefController(MsgFactory.java:46)
at org.olat.core.gui.components.Window.dispatchRequest(Window.java:589)
at org.olat.core.gui.components.Window.doDispatchRequest(Window.java:282)
at org.olat.core.gui.components.AbstractComponent.dispatchRequest(AbstractComponent.java:193)
at org.olat.dispatcher.AuthenticatedDispatcher.processValidDispatchURI(AuthenticatedDispatcher.java:273)
at org.olat.dispatcher.AuthenticatedDispatcher.execute(AuthenticatedDispatcher.java:190)
at org.olat.core.servlets.OpenOLATServlet.executeUserRequest(OpenOLATServlet.java:294)
at org.olat.core.servlets.OpenOLATServlet.doPost(OpenOLATServlet.java:237)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)

stack of 2.cause::java.lang.IllegalArgumentException: MALFORMED[1] -> 
at com.sun.nio.zipfs.ZipCoder.toString(ZipCoder.java:70)
at com.sun.nio.zipfs.ZipCoder.toString(ZipCoder.java:78)
at com.sun.nio.zipfs.ZipFileSystem.getString(ZipFileSystem.java:916)
at com.sun.nio.zipfs.ZipPath.toString(ZipPath.java:540)
at org.olat.course.certificate.ui.UploadCertificateController$IndexVisitor.visitFile(UploadCertificateController.java:274)
at org.olat.course.certificate.ui.UploadCertificateController$IndexVisitor.visitFile(UploadCertificateController.java:258)
at java.nio.file.Files.walkFileTree(Files.java:2670)
at java.nio.file.Files.walkFileTree(Files.java:2742)
at org.olat.course.certificate.ui.UploadCertificateController.validateHtml(UploadCertificateController.java:190)
at org.olat.course.certificate.ui.UploadCertificateController.validateTemplate(UploadCertificateController.java:174)
at