“DLL load failed while importing fmeobjects: A dynamic link library (DLL) initialization routine failed.”

I can't really check this myself because I can't install the ArcGIS Pro version but are you willing to try installing FME 2024.2? If it does work with that version of FME it might be a bug in the 2025 version.

I just tried it with 2024.2, it still doesn’t work. The only way that I can get it to work is to use ArcPro 3.1.7 or earlier. 

Do you have two ArcGIS Pro versions installed? FME can't deal with that, ESRI also indicates that having two versions of Pro on your pc can cause issues.

No, only one version installed.

Hmmm, I have only one idea left to be honest. Can you post your ArcGIS Pro version?

It is: 3.3.5 

It also doesn’t work for 3.4.x or any 3.3.x

It does work for 3.1.7.

Unfortunately I don't know what else it can be. Maybe someone will come by here who has a better idea or maybe contact Safe. Is there a specific reason you want to use the 3.3.5 version?(I am just curious) 

Potential workaround if all you need to do is run your FME workbench from a python script is to remove the python FME objects from the equation and run it through command line (in python, it would be through the standard subprocess module).

I would first manually verify your workbench works on a regular command line but if it does…...

You could do something like this (just change or remove the user parameters as needed etc):

import subprocess
import os
import sys

def fmeworker(workbench, f, logpath):
    '''fmeworkber function automates the execution of a workbench through the python
    subprocess method. The subprocess.Popen() executes the command and retrieves the process outputs to stdout and stderr.
    workbench = the fme .fmw workbench to run; full path str
    f = example user parameter 1 of the workbench; feature class str
    logpath = example user parameter 2 of the workbench; path to log.txt output str
    '''
    #
    text = ''
    try:
        fme_ = r"C:\Program Files\FME\fme.exe" ##fme.exe; change this based on your installation
        command = f'"{fme_}" "{workbench}" --FEATURE_TYPES "{f}" --LogFile "{logpath}"'
        starter = subprocess.STARTUPINFO()
        starter.dwFlags |= subprocess.STARTF_USESHOWWINDOW

        process = subprocess.Popen(command,startupinfo=starter, stdout=subprocess.PIPE,stderr=subprocess.PIPE)
        stdout,stderr = process.communicate()
        if stderr:
            stderr_de = str(stderr.decode("utf-8")) # Need to remove byte object
            msg = stderr_de.split("\r\n")n0]
            text += f +'  '+ msg
        else:
            stdout_de = str(stdout.decode("utf-8")) # Need to remve byte object
            msg = stdout_de.split("\r\n")n0]
            text += msg+'ERROR#####'
    except:
        #if the workbench function fails add error tag
        text += f +'ERROR#####'
    return text

Which can give you a return output from your workbench if it was successful or not:
 

For others having this same problem: it’s a dll mismatch between ArcPro 3.3.5 python environment’s msvcp140* dlls and new versions required for fmeobjects (in my case, I am using FME 2025.0 right now but it applies to many other versions).

To fix this (at your own risk), rename msvcp140*.dll files in C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\ to msvcp140*.dllignore. If you have a customized environment elsewhere, you will need to do it there as well. It’s usually something along the lines of C:\Users\<user>\AppData\Local\ESRI\conda\envs\<env_name>.