GRAIL ERROR (v3/touch.cpp:~Touch:84)

Using uTouch-GEIS to add/remove subscriptions to windows sometimes I get this error:

Failed to copy non-existent touch
Failed to copy non-existent touch
Failed to copy non-existent touch
GRAIL ERROR (v3/touch.cpp:~Touch:84): touch 1430 failed to be rejected
GRAIL ERROR (v3/touch.cpp:~Touch:84): touch 1429 failed to be rejected
GRAIL ERROR (v3/touch.cpp:~Touch:84): touch 1428 failed to be rejected
Warning: failed to get previous touch value
Warning: failed to get previous touch value

This is my code:

            GeisFilter filter = geis_filter_new(this->geis, "filter");

            geis_filter_add_term(filter,
                    GEIS_FILTER_CLASS,
                    GEIS_GESTURE_ATTRIBUTE_TOUCHES, GEIS_FILTER_OP_EQ,
                    numFingers,
                    GEIS_CLASS_ATTRIBUTE_NAME, GEIS_FILTER_OP_EQ,
                    gesture.toStdString().c_str(),
                    NULL);

            geis_filter_add_term(filter, GEIS_FILTER_REGION,
                    GEIS_REGION_ATTRIBUTE_WINDOWID, GEIS_FILTER_OP_EQ, w, NULL);

            GeisSubscription subscription = geis_subscription_new(
                    this->geis, "subscription", GEIS_SUBSCRIPTION_CONT);
            geis_subscription_add_filter(subscription, filter);
            geis_subscription_activate(subscription);