Upload problem 'no JSON'

Dear all, dear @Ludee ,
I have been putting together a script to upload input and output of the OSeMBE model developed in the H2020 REEEM project to the OEP.
I'm not (yet) very skilled in coding. When putting together the script I basically took elements from scripts for the REEEMdb and the OEP example script for uploading csv's.
The script is not very beautiful, but I think it is not far away from working. However, when running it it throws the message: 'raise ConnectionException('Answer contains no JSON: ' + repr(ans))
ConnectionException: Answer contains no JSON: <Response [404]>'
To me it looks like it is asking for including a JSON license file. However, in the example OEP script this is not required.
Could you @Ludee perhaps have a look? Or someone else who can spare some minutes?
Thanks in advance!
Best,
Hauke

`
import os
import time
import getpass
import logging
from sqlalchemy import *
import configparser as cp
import pandas as pd
import oedialect

parameter

config_file = 'oep_io_config.ini'
config_section = 'oep'
log_file = 'oep_adapter.log'

sys.tracebacklimit = 0

cfg = cp.RawConfigParser()

#%% logger
def logger():
"""Configure logging in console and log file.

Returns
-------
rl : logger
    Logging in console (ch) and file (fh).
"""

# set root logger (rl)
rl = logging.getLogger('REEEMLogger')
rl.setLevel(logging.INFO)
rl.propagate = False

# set format
formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s',
                              datefmt='%Y-%m-%d %H:%M:%S')

# console handler (ch)
ch = logging.StreamHandler()
ch.setLevel(logging.INFO)
ch.setFormatter(formatter)
rl.addHandler(ch)

# file handler (fh)
fh = logging.FileHandler(log_file)
fh.setLevel(logging.INFO)
fh.setFormatter(formatter)
rl.addHandler(fh)

return rl

#%% OEP session
def oep_session():
user = input('Enter OEP-username:')
token = getpass.getpass('Token:')

OEP_URL = 'openenergy-platform.org'
OED_STRING = f'postgresql+oedialect://{user}:{token}@{OEP_URL}'

engine = create_engine(OED_STRING)
metadata = MetaData(bind=engine)
print(metadata)

conn = engine.connect()
print('Connection established')
return conn

#%% Scenario log
def scenario_log(con, project, version, io, schema, table, script, comment):
"""Write an entry in scenario log table.

Parameters
----------
con : connection
    SQLAlchemy connection object.
project : str
    Project name.
version : str
    Version number.
io : str
    IO-type (input, output, temp).
schema : str
    Database schema.
table : str
    Database table.
script : str
    Script name.
comment : str
    Comment.

"""

sql_scenario_log_entry = text("""
    INSERT INTO OSeMBE-data.scenario_log
        (project,version,io,schema_name,table_name,script_name,entries,
        comment,user_name,timestamp,metadata)
    SELECT  '{0}' AS project,
            '{1}' AS version,
            '{2}' AS io,
            '{3}' AS schema_name,
            '{4}' AS table_name,
            '{5}' AS script_name,
            COUNT(*) AS entries,
            '{6}' AS comment,
            session_user AS user_name,
            NOW() AT TIME ZONE 'Europe/Berlin' AS timestamp,
            obj_description('{3}.{4}' ::regclass) ::json AS metadata
    FROM    {3}.{4};""".format(project,version, io, schema, table, script,
                               comment))

con.execute(sql_scenario_log_entry)

#%% Filename split following REEEM conventions
def reeem_filenamesplit(filename):
"""file name identification"""

filenamesplit = filename.replace(".xlsx", "").replace(".csv", "").split("_")
fns = {}
fns['day'] = filenamesplit[0]
fns['pathway'] = filenamesplit[1]
fns['model'] = filenamesplit[2]
fns['framework'] = filenamesplit[3]
fns['version'] = filenamesplit[4]
fns['io'] = filenamesplit[5]
return fns

#%% Sending OSeMBE df to OEP db
def osembe_2_oep_db(filename, fns, empty_rows, schema_name, region, con):
"""read excel file and sheets, make dataframe and write to database"""

# read file
path = os.path.join('Model_Data', filename)
xls = pd.ExcelFile(path)
df = pd.read_excel(xls, region, header=empty_rows, index_col='ID')
log.info('...read sheet: {}'.format(region))

# make dataframe
df.columns = ['indicator', 'unit',
              '2015', '2016', '2017', '2018', '2019', '2020', '2021',
              '2022', '2023', '2024',
              '2025', '2026', '2027', '2028', '2029', '2030', '2031',
              '2032', '2033', '2034',
              '2035', '2036', '2037', '2038', '2039', '2040', '2041',
              '2042', '2043', '2044',
              '2045', '2046', '2047', '2048', '2049', '2050', 'category',
              'aggregation']
df.index.names = ['nid']
# print(df.head())
# print(df.dtypes)

# seperate columns
dfunit = df[['category', 'indicator', 'unit', 'aggregation']].copy().dropna()
dfunit.index.names = ['nid']
dfunit.columns = ['category', 'indicator', 'unit', 'aggregation']
# print(dfunit.head())
# print(dfunit.dtypes)

# drop seperated columns
dfclean = df.drop(['category', 'indicator', 'unit', 'aggregation'],
                  axis=1).dropna()
# print(dfclean.head())
# print(dfclean)

# stack dataframe
dfstack = dfclean.stack().reset_index()
dfstack.columns = ['nid', 'year', 'value']
# dfstack.set_index(['nid','year'], inplace=True)
dfstack.index.names = ['id']
# print(dfstack)

# join dataframe for database
dfdb = dfstack.join(dfunit, on='nid')
dfdb.index.names = ['dfid']
dfdb['pathway'] = fns['pathway']
dfdb['framework'] = fns['framework']
dfdb['version'] = fns['version']
dfdb['region'] = region
dfdb['updated'] = fns['day']

print(dfdb)

# dfdb['updated'] = (datetime.datetime.fromtimestamp(time.time())
#     .strftime('%Y-%m-%d %H:%M:%S'))
# print(dfdb.head())

# copy dataframe to database
dfdb.to_sql(con=con,
            schema=schema_name,
            name=db_table,
            if_exists='append',
            index=True)
log.info('......sheet {} sucessfully imported...'.format(region))

#%% Input
filenames = [
'2019-07-29_B0C0T0E0_OSeMBE_FrameworkNA_DataV2_Input.xlsx',
'2019-07-29_B0C0T0E0_OSeMBE_FrameworkNA_DataV2_Output.xlsx' ]

regions = ['EU+CH+NO', 'AT', 'BE', 'BG', 'CH', 'CY', 'CZ', 'DE', 'DK', 'EE',
'ES', 'FI', 'FR', 'GR', 'HR', 'HU', 'IE', 'IT', 'LT', 'LU',
'LV', 'MT', 'NL', 'NO', 'PL', 'PT', 'RO', 'SE', 'SI', 'SK',
'UK']

empty_rows = 5

database table

schema_name = 'OSeMBE-data'
db_table_input = 'reeem_osembe_input'
db_table_output = 'reeem_osembe_output'

#%%
if name == 'main':

# logging
log = logger()
start_time = time.time()
log.info('script started...')

# connection
con = oep_session()
log.info('...read file(s)...')

# import files
for filename in filenames:

    # file and table
    fns = reeem_filenamesplit(filename)
    
    # i/o
    if fns['io'] == "Input":
        db_table = db_table_input
    else:
        db_table = db_table_output

    # log files
    log.info('read file: {}'.format(filename))
    log.info('...model: {}'.format(fns['model']))
    log.info('...pathway: {}'.format(fns['pathway']))
    log.info('...framework: {}'.format(fns['framework']))
    log.info('...version: {}'.format(fns['version']))
    log.info('...i/o: {}'.format(fns['io']))
    log.info('...regions: {}'.format(regions))
    log.info('...database table: OSeMBE-data.{}'.format(db_table))

    # import
    for region in regions:
        osembe_2_oep_db(filename, fns, empty_rows,
                        schema_name, region, con)

    # scenario log
    #scenario_log(con, 'REEEM', __version__, 'import', schema_name, db_table,
     #           os.path.basename(__file__), filename)


# close connection
con.close()
log.info('...script successfully executed in {:.2f} seconds...'
         .format(time.time() - start_time))
log.info('...database connection closed. Goodbye!')`

Start with the pasted upload script, especially the oep_session and scenario_log entry points, and reproduce the 404 response using the stated OEP connection. Trace which request returns no JSON and confirm the upload completes for the listed OSeMBE input and output files without the exception.