Hashicorp vault custom plugin unsupported path

Question

I'm writing a custom plugin for Hashicorp vault in golang. I created a backend server to handle the plugin requests

err := plugin.Serve(&plugin.ServeOpts{
    BackendFactoryFunc: backend.Factory,
    TLSProviderFunc:    tlsProviderFunc,
})
if err != nil {
    log.Println(err)
    os.Exit(1)
}

In the backend server I registered two paths:

func Backend() (*backend, error) {
    var b backend
    b.Backend = &framework.Backend{
        Help: "",
        Paths: framework.PathAppend(
            registerFoo1(&b),
            registerFoo2(&b),
        ),
        PathsSpecial: &logical.Paths{
            SealWrapStorage: []string{
                "foo1/",
                "foo2/",
            },
        },
        Secrets:     []*framework.Secret{},
        BackendType: logical.TypeLogical,
    }
    return &b, nil
}

The requests to foo1 are received and handled, but the plugin ignored requests to foo2.

The error message is: {"errors":["1 error occurred:\n\t* unsupported path\n\n"]}. The error message raises in different HTTP verbs.

Both paths have their own module inside the package(foo1.go and foo2.go)

foo1.go

func registerFoo1(b *backend) []*framework.Path {
    var paths = []*framework.Path{
        foo1(b),
    }
    return paths
}
func (b *backend) foo1(ctx context.Context, req *logical.Request,
data *framework.FieldData) (*logical.Response, error) {
...
name := data.Get("name").(string)
...
}

foo2.go

func registerFoo2(b *backend) []*framework.Path {
    var paths = []*framework.Path{
        foo2(b),
    }
    return paths
}
func (b *backend) foo2(ctx context.Context, req *logical.Request,
data *framework.FieldData) (*logical.Response, error) {
...
var1 := data.Get("name").(string)
anothervar, err := b.getsomedata(ctx, req, address)
    if err != nil {
        b.Logger().Error("cannot get data: ", err.Error())
        return nil, err
    }
...
}