  Applying geometric methods of $2$-dimensional cell complex theory, we
construct a Galois covering of a bimodule problem satisfying some structure,
triangularity and finiteness conditions in order to describe the objects of
finite representation type. Each admitted bimodule problem $\mathcal A$ is
endowed with a quasi multiplicative basis. The main result shows that for a
problem from the considered class having some finiteness restrictions and the
schurian universal covering $\tilde{\mathcal A}$, either $\mathcal A$ is
schurian, or its basic bigraph contains a dotted loop, or it has a standard
minimal non-schurian bimodule subproblem.
