“Compilation failed (return status=1)” exception when running PyMC3 model

I get this error:

Exception: ('Compilation failed (return status=1): cc1plus.exe: sorry, unimplemented: 64-bit mode not compiled in. ', 'FunctionGraph(Elemwise{add,no_inplace}(TensorConstant{1.0}, TensorConstant{1.0}))')

when I try to run this model:

np.random.seed(123)
n_experiments = 4
theta_real = 0.35
data = stats.bernoulli.rvs(p=theta_real, size= n_experiments)

firstModel= pm.Model()
with firstModel:
    theta=pm.Beta( 'theta', alpha=1, beta=1)
    y= pm.Bernoulli('y', p=theta, observed= data)
    trace=pm.sample(1000, cores= 4)

The model was working fine but after installing MinGW, I started getting this error. I’m using python 3.9 and PyMC3 3.11.2 installed through PyPI (I’m not using conda and for some technical reasons can’t use conda on my current machine). Also, when I first import PyMC3, I get a warning that: WARNING (theano.tensor.blas): Using NumPy C-API based implementation for BLAS functions.