Adobe Flash Player 9 - Where is the debugger or host Application Running
Adobe Flash Player 9 application has some missing component. Sometimes when a user opens a website, even he has a working installation of Flash Player, he will get this prompt message. I used to visit a website regularly and that website gave me always this prompt. I thought that the website has something to do with it and when I clicked at "Don't connect", it always disappeared. Then I got this prompt today at my own website. I had to find some solution. Try these methods which have worked for me:

How to fix the Flash Player 9 debugger problem
There can be two possible solutions.
First Solution
When the page opens, the element that is causing the problem will not be shown correctly. Right click at that and click at Debugger if the prompt is not opened already or you just cancelled it. This will bring the prompt again.
It will ask that where the debugger or host application is running and will provide two choices:
- Localhost
- Other Machine
- Select Other Machine
- Write in the IP Address box Local Machine Address i.e. 127.0.0.1
- Check the box which says Don't show this dialogue at launch
- Click connect button
Problem should be solved and if you are running Flex Builder then you will notice the change that the connection has been successful.
Second Solution
- If your being prompted with this dialog box in Internet Explorer, Download and install Flash Player 9 ActiveX control content debugger (for IE)
- If your being prompted with this dialog box in Firefox, Download and install Flash Player 9 Plugin content debugger (for Netscape-compatible browsers)
If all goes well, your Flash Player 9 Debugger issues should be resolved.
[ For more, Please read comments, to see how people managed to fix it ]




hi Says:
hi. i have tried the IP address solution but the same window that is asking where the host application or host application appears.
can i install flash 9 again will this solve the problem?
Hiroshi Says:
No, it won’t help reinstalling Flash. You can try SECOND SOLUTION above. Download fix and install that.
JJ Says:
I came across the same problem in Linux using Flex Builder with FP 9, neither way works. Comments?
Hiroshi Says:
Linux users: Updated Linux debugger versions (aka debug players or content debuggers) of Flash Player 9 are now available. Additionally, the Linux standalone player (projector) is available for developers who wish to publish projectors on Linux operating systems. Download following update and install it.
http://download.macromedia.com/pub/flashplayer/updaters/9/flash_player_9_linux_dev.tar.gz
More help & download options: http://www.adobe.com/support/flashplayer/downloads.html
JJ Says:
I have been using the FP bundled within Flex builder. I guess I should install the plugin version debugger. But it’s not clear to me if I should replace the FP in Flex builder.
Hiroshi Says:
@JJ: I suggest you to replace.
Alex Says:
thanks for the post – i’m on google crome and get the exact same message on espn.com and some other sites – it’s annoying.
the ip solution didn’t work for me…any other ideas?? thanks.
Ron Says:
Operating System: Windows Vista
Browser: Google Chrome
Problem: Nearly every flash based application that I have come across online has caused this error. It doesn’t seem to occur in Firefox nor Internet Explorer. Is there a Flash Player plugin for Chrome?
Thanks.
Hiroshi Says:
@Ron: http://get.adobe.com/flashplayer/otherversions/
If we go for adobe flash plugin. It is available for Vista, supporting IE and Firefox but there is no release for Google Chrome Browser yet. As soon as I find some solution, I will let you know.
http://www.google.com/chrome
Google Chrome is in beta phase. Its support in other applications will have to wait I think.
Hiroshi Says:
If there will be any update or solution regarding above problem, it will be found on these two URLs.
http://www.adobe.com/support/documentation/en/flashplayer/9/releasenotes.html
http://www.adobe.com/support/flashplayer/downloads.html
Alex Says:
thanks!
Alex Says:
thanks for the help / links…the second one where i got the latest version seems to have solved the problem!
Hiroshi Says:
@Alex: Glad to hear that problem is solved.
Bugnguts Says:
Thank you Hiroshi. I was getting very frustrated, almost to the point of likingAdobe to AOL, which is the gravest of insults. Now with lower blood pressure my life expectancy is extended by a couple weeks. Thanks.
sathish Says:
i am working in mozila firefox. where is the debugger or host application running message displayed. please tell hiroshi
André G. Bottan Says:
Hi Hiroshi! (forgive my bad english)
I have this ‘debugger-window-problem’ and I was seeking for a solution.
This post of yours is very nice, but it did not solved my problem. I have, indeed, some difficulties in understanding it.
I’m asking to you for some better explanation. (May I’m being a little stupid, hehehehe. So help me please)
So… Where the “Don’t show this dialogue at launch” checkbox is on the window-image. I’m using Windows XP/SP2 (too much old, perhaps?), and my ‘debugger-window’ does not have this check, like the image on the post, and the flash context menu does not have it too.
I found in another site a “Windows Vista” version of this danmmed windows, and it had the checkbox.
It is in
http://www.lancelhoff.com/where-is-the-debugger-or-host-application-runnin/
Wich operational system are you refering in this tutorial?
Ahn… I tried the ‘install-patch’ for Firefox (the browser tha I’m using) and the installation did not worked.
In any case, I’m glad that keen people like you give attention to these boring problems.
Thank you, in advance.
Hiroshi Says:
@André G. Bottan: @sathish: The solution is to update FireFox to the latest version:
http://www.mozilla.com/en-US/firefox/
and download latest flash player plugin from Adobe.
http://get.adobe.com/flashplayer/
I have the latest versions which definitely fix the problem.
And if you still experiencing problem for the flash player 9 debug and flex thing, please proceed here for activex control content debugger:
http://www.adobe.com/support/flashplayer/downloads.html#fp9
melvin Says:
sir .. why you dont have the fix for OPERA.. im freakin out sir for that debugger.. help pls..
André G. Bottan Says:
Hi Hiroshi!
I donwloaded and installed the latest Flash Player that you recommended, and it fixed the problem. Since my last post the annoying screen didn’t popped again. I’m just “feedbacking” you about it.
Thank you very much for the tip!
Hiroshi Says:
@André G. Bottan: Thank you.
david Says:
It worked. Thanks alot
Donnie Fair Says:
Upgrade to Flash 10.x solved my problems w/ Chrome.
Peppy Says:
Thanks bro! i love you! <3!
Lydia Says:
Thank you!!!!!!
Dewi Says:
Thanks a lot!!!
It’s really helping
dextor Says:
Solution two works…
my firefox was crashing…
after installing the debugger which you mentioned above,
its working correctly..
fredy Says:
thanks, Upgrade to Flash 10 resolved the problem!!!
Mariel Says:
THANK GOD! and thank you too! This message kept showing and was driving me mad!
Hello World Says:
I recommend the second method its more convenient , techmynd Thank You Very much ^_^
Steve Says:
I used the 2nd solution and it worked perfecto :) Thank you very much.
Gustavo Says:
I tested the second solution for Firefox, very easy and simple, and so far it worked! (Hopefully it will stay working!)
And, in my case, often Firefox stopped working when that annoying message showed up, so thanks a lot!