Nop Upgrade 3.10 to 3.50 - Page not found

the first page is well displayed but when I click on an object ,I've "page not found" error message.

the url is : "http://localhost:15536/FR/FR/customer/info" on my localhost.

Is-it normal twice FR ?

Other test:

Change language to English : page not found

Test to access to administration page :
http://localhost:15536/FR/FR/admin - -> page not found

I try without' FR/FR/' :

http://localhost:15536/admin -> Ok, the administration page is displayed now

What can I do to solve that please ?

All seems right in Administration pages...
I import successfully each language packaqe (FR and DE) for 3.5 : no error : OK

Following the idea to change VS2012 -> VS2013, I try that and come here later...

see : here

Hi
I've try to use Visual Studio 2013
I've the same issue :

"Page not found" for any language

What could be the solution please ?