upgrade from G3.0 b3 to G3.o RC1 problem

Hi guys
I had installed Gallery 3.0 beta 3 witch SMK theme. Everything was working perfect.
Don't know why, I've made life more complicated and decided to upgrade to RC1.
After "successfully" upgrade the only different I found s far is that, I can not go to Administration panel. Believe it must be SMK theme problem. dang.. something wrong
....but I'm admin so U can tell me stuff

"
So here's the error:
The requested view, admin.html, could not be found

Plik(plik mean file): system/core/Kohana.php, linia(line): 1162
And here's how we got there:

* system/libraries/View.php [84]:

Kohana::find_file( views, admin.html, 1 )

* system/libraries/View.php [50]:

View_Core->set_filename( admin.html )

* modules/gallery/libraries/MY_View.php [27]:

View_Core->__construct( admin.html )

* modules/gallery/libraries/Admin_View.php [36]:

View->__construct( admin.html )

* modules/gallery/controllers/admin_dashboard.php [22]:

Admin_View_Core->__construct( admin.html )

*

Admin_Dashboard_Controller->index( )

* modules/gallery/controllers/admin.php [50]:

call_user_func_array( Array
(
[0] => Admin_Dashboard_Controller Object
(
[theme:Admin_Controller:private] =>
[uri] => URI Object
(
)

[input] => Input Object
(
[use_xss_clean:protected] => 1
[magic_quotes_gpc:protected] => 1
[ip_address] =>
)

)

[1] => index
)
)

*

Admin_Controller->__call( index )

* system/core/Kohana.php [291]:

ReflectionMethod->invokeArgs( Admin_Controller Object
(
[theme:Admin_Controller:private] =>
[uri] => URI Object
(
)

[input] => Input Object
(
[use_xss_clean:protected] => 1
[magic_quotes_gpc:protected] => 1
[ip_address] =>
)

)
, Array
(
[0] => index
[1] => Array
(
)

)
)

*

Kohana::instance( )

* system/core/Event.php [209]:

call_user_func( Array
(
[0] => Kohana
[1] => instance
)
)

* system/core/Bootstrap.php [55]:

Event::run( system.execute )

* /library/webserver/documents/index.php [86]:

require( system/core/Bootstrap.php )

"

HELP, I can NOT lost all my comments, I'll be lucky if will get just killed

thanks for quick reply Dave
what I've done, create new folder (gallery3) in my main Gallery folder, and I copied my existing var to new galery3 folder.

thanks for help again, I'm starting to read link U give me now
have a good Sunday mate

damn, I've done it again, now gallery crashed even for guests

it is my server
mac osx 10.6
apache 2.2.13
php 5.30
mysql 5.1.39

don't have backup of db. before update made copy of gallery but not db (handy)
during upgrade forgot to change name of old gallery

moral

- don't do anything importand when U tired
- don't donate if U have something for free

thanks for response

"Huh? Sorry, I don't speak 12 year old text speak." don't understand

decide to delete everything , and install new version with new db.
It took me a while, but uploaded all old pictures. Unfortunately lost comments etc
It is lesson for me to do backups of my websites
Read a lot of your answers for posts witch similar problems, but ... doesn't matter now

I like RC1 very much,
so far I found one problem only witch uploading .flv files (same files was uploaded just fine in beta3)
i'll sort it out some how later. Important is that my parents can view new pictures of their grandson.

And I'll never again install 3rd party themes again