This is a known issue (reference #JIRASOSSE2935) and can occur on older version as well.
The workaround:
Open home pages of the Windows connections in trouble by a Spotlight Diagnostic Administrators' member.
Then accesses from a read-only user will have no problems.
This problem will occurs for read-only users when they (the first user among them only) tries to open a Windows Connection that has not been opened by the Admin user since its creation.
So the better workaround is that each time Windows connection is created, the spotlight admin user might want to open the homepage first before read only user will do it.
This is not a client specific problem. The Admin user can use any client to firstly open the Windows connection home.
This is a one-off problem for each Windows connection.