prophet: Python3.7.0: Something went wrong while unpickling the StanModel. Consider recompiling.

OS: Windows 7 Professional

First of all, I have read through related threads #249 #252 and #599, but still cannot figure out how to solve this issue.

I understand that the easiest way to install fbprophet is to run conda install -c conda-forge fbprophet but for reasons I don’t know, it takes forever for conda to solve the environment. It’s not the case if I use conda to install other packages. So instead I used pip and it reported that fbprophet 0.4 was installed successfully. But I then got the following error message when importing fbprophet WARNING:pystan:No module named ‘stanfit4anon_model_861b75c6337e237650a61ae58c4385ef_2841341000846931969’ WARNING:pystan:Something went wrong while unpickling the StanModel. Consider recompiling.

Before installing fbprophet, I followed this instruction to install pystan and checked that pystan is working properly. By running the following code. import pystan model_code = 'parameters {real y;} model {y ~ normal(0,1);}' model = pystan.StanModel(model_code=model_code) # this will take a minute y = model.sampling(n_jobs=1).extract()['y'] y.mean() # should be close to 0

I got message like

Gradient evaluation took 0 seconds 1000 transitions using 10 leapfrog steps per transition would take 0 seconds. Adjust your expectations accordingly!

Iteration: 1 / 2000 [ 0%] (Warmup) Iteration: 200 / 2000 [ 10%] (Warmup) Iteration: 400 / 2000 [ 20%] (Warmup) Iteration: 600 / 2000 [ 30%] (Warmup) Iteration: 800 / 2000 [ 40%] (Warmup) Iteration: 1000 / 2000 [ 50%] (Warmup) Iteration: 1001 / 2000 [ 50%] (Sampling) Iteration: 1200 / 2000 [ 60%] (Sampling) Iteration: 1400 / 2000 [ 70%] (Sampling) Iteration: 1600 / 2000 [ 80%] (Sampling) Iteration: 1800 / 2000 [ 90%] (Sampling) Iteration: 2000 / 2000 [100%] (Sampling)

Elapsed Time: 0.01 seconds (Warm-up) 0.01 seconds (Sampling) 0.02 seconds (Total)

I uninstalled both pystan and fbprophet and then reinstalled them with --no-cache flag. But fbprophet still didn’t work.