Can't reinstall or update app with cert problem

[Ihor]

I have made small changes in my Desktop App, Flex+Air and now I can't install this app with same app id, like com.adobe.myapp/ After compile project I recive every time error on install my app.

"

Sorry, an error has occured

The application cannot be installed due to a certificate problem.  The certificate does not match the installed application certificate, does not support application upgrades, or is invalid.  Please contact the application author.

"

if app-id changed  I recive new error that: App can't be installed in same folder, and I can compile and istall only if I change App name and App Id< but in this case my app will lost all settings and DB files.

As I see, now Adobe AIR 4.0 made limits for counts of instalations. Why? Now I need to write to all manuals how to uninstall and move all files and settings for each users? Why I can't more update and install my app.

[John_Hall]

No intention of being patronizing but you've uninstalled the app and tried again?

[Ihor]

I found solution.

I have lost my old cert file (p12), and with new creacted cert file I can't more update my App in same folder with same name, also I can't help all my clients to solve this. After uninstalll App, alll clients will lost files and settings.

I can't find solution how I can restore my old cert.p12 file from old AIR app. In this case I need to close my project and don't provide updates any more/