# Error launching client/designer with \_ in hostname

**URL:** <https://forum.inductiveautomation.com/t/error-launching-client-designer-with---in-hostname/7946>\
**Category:** Ignition\
**Created:** [February 3, 2014, 4:51pm UTC](https://forum.inductiveautomation.com/t/error-launching-client-designer-with---in-hostname/7946 "2014-02-03T16:51:42Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![jay](https://avatars.discourse-cdn.com/v4/letter/j/ed8c4c/32.png) [@jay](https://forum.inductiveautomation.com/u/jay)\
**Post date:** [February 3, 2014, 4:51pm UTC](https://forum.inductiveautomation.com/t/error-launching-client-designer-with---in-hostname/7946/1 "2014-02-03T16:51:42Z")

</div>

Ingnition version 7.6.5 rc1 . This works fine if I use the IP address instead of the hostname.

Launch File:  
   
  
  
Ignition Designer  
Inductive Automation

Expecption:  
   
ava.lang.SecurityException: unexpected excpetion  
at com.sun.deploy.security.ruleset.RuleId.pathIncludes(Unknown Source)  
at com.sun.deploy.security.ruleset.RuleId.compareStringToURL(Unknown Source)  
at com.sun.deploy.security.ruleset.RuleId.onExceptionList(Unknown Source)  
at com.sun.deploy.security.ruleset.RuleId.isException(Unknown Source)  
at com.sun.deploy.security.ruleset.DeploymentRuleSet.getDefaultOrException(Unknown Source)  
at com.sun.deploy.security.ruleset.DeploymentRuleSet.getDRS(Unknown Source)  
at com.sun.deploy.security.ruleset.DeploymentRuleSet.findDRS(Unknown Source)  
at com.sun.javaws.jnl.LaunchDesc.getMainDeploymentRuleSet(Unknown Source)  
at com.sun.javaws.jnl.LaunchDesc.getMatchImpl(Unknown Source)  
at com.sun.javaws.jnl.LaunchDesc.getJREMatcher(Unknown Source)  
at com.sun.javaws.Launcher.prepareLaunchFile(Unknown Source)  
at com.sun.javaws.Launcher.prepareAllResources(Unknown Source)  
at com.sun.javaws.Launcher.prepareToLaunch(Unknown Source)  
at com.sun.javaws.Launcher.prepareToLaunch(Unknown Source)  
at com.sun.javaws.Launcher.launch(Unknown Source)  
at com.sun.javaws.Main.launchApp(Unknown Source)  
at com.sun.javaws.Main.continueInSecureThread(Unknown Source)  
at com.sun.javaws.Main.access$000(Unknown Source)  
at com.sun.javaws.Main$1.run(Unknown Source)  
at java.lang.Thread.run(Unknown Source)  
Caused by: java.net.URISyntaxException: Illegal character in hostname at index 10: [mwd\_ws1/main/system/launch/desig … igner.jnlp](http://mwd_ws1/main/system/launch/designer/designer.jnlp)  
at java.net.URI$Parser.fail(Unknown Source)  
at java.net.URI$Parser.parseHostname(Unknown Source)  
at java.net.URI$Parser.parseServer(Unknown Source)  
at java.net.URI$Parser.parseAuthority(Unknown Source)  
at java.net.URI$Parser.parseHierarchical(Unknown Source)  
at java.net.URI$Parser.parse(Unknown Source)  
at java.net.URI.(Unknown Source)  
at java.net.URI.(Unknown Source)  
… 20 more

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [February 3, 2014, 5:06pm UTC](https://forum.inductiveautomation.com/t/error-launching-client-designer-with---in-hostname/7946/2 "2014-02-03T17:06:07Z")

</div>

You know… it turns out that an underscore is not a valid character in a hostname. It’s valid for domain names, and possibly for use in subdomains, but when it comes to the hostname of a URI/URL you can only use letters-digits-hyphens.