<roleManager defaultProvider="MASSIARoleProvider" enabled="true" cacheRolesInCookie="true">
<providers>
<clear />
<add name="MASSIARoleProvider" type="MASSIA.Helpers.MASSIARoleProvider" connectionStringName="MASSIAEntities" />
</providers>
</roleManager>
Attemp 2:
Check for your MASSIARoleProvider file and see whether the Solution name and references used are perfectly correct.
Attempt 3:
The last and least recommended.
Create a new solution, if and only if your solution is in the beginning stage and try to reconfigure the RoleProvider. Once it solved the issue for me, I made a new solution, added the existing files to the news solution and executed the new solution and it executed perfectly. I did not made any change to the code, i just included the existing files from the old solution to the new one.