Lack of controls on customer's properties form after an upgrade 1.40 -> 1.50

Hello,
Logged as an admin, when I choose 'edit' any customer - no matter if me or anybody else - I see a form with "Back to the customers list" link (and user icon) only. No fields, no controls below (top menu exists).
The problem appear after succesful upgrade from 1.40 to 1.50.
Any advice, if you please?

Edward

hello Edward ,

You don't even see the admin user in the customer list ?

Did you check system log ? Your upgrade might did something by which you're facing this problem, go to admin section > System > Log

Look for any error message, if you see any error message, post that error msg here

Hello Mike,
I've noticed that all the pages in Administration folder are not processed. Blank page, which I see, is in fact the result of 404 error.
Looks that's a problem with my hosting server configuration. I have to check how to fix it through web.config parameters.

1) your web hosting company provided you full write permission and full trust ?

2) which browser you're using ?

3) when you did the updation , did you get any error message ? or it was a successful upgrade ? And, this problem started right after the update or for few days / some time it worked fine ?

4) Do you have any log error messages ?

1) they provide full write permission and full trust

2) mostly Firefox, less IE (I tried to access Adm. functions in both the browsers - without effect)

3) it was a successful upgrade, then trying to grant one user with adm. permission I noticed the problem

4) The only error in nopcommerce log says:
Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

Beside of it there are 404 errors in IIS logs, referring to the Adm. pages.

Please take a look at this thread:

https://www.nopcommerce.com/boards/topic.aspx?topicid=2857

you can take a look at this too : http://forums.asp.net/t/955145.aspx?PageIndex=9