Towards the correct prescription of the Problem of divergence of Propagator of Siegal-Zwiebach action from String theory in Fierz-Pauli Gauge in the small mass limit

In the present work we will give an explicit solution the problem of divergence of propagator of gauge-invariant Siegel-Zwiebach action in Fierz-Pauli gauge in massless limit by connecting its Greens functions to that of Transverse-Traceless gauge using improved finite-field-dependent BRST method.