FME Flow Troubleshooting: Flow Apps

Matt Meeboer
Matt Meeboer
  • Updated
Full Guide: FME Flow Troubleshooting Guide

Is your FME Flow App (formerly FME Server App) not working as you intended? Are you seeing unexpected user-interface issues? 
Please read below for some common troubleshooting tips, questions, and resources.

In 2023, FME Server underwent a name change and is now known as FME Flow. Since this article discusses features present in previous versions of FME, it will refer to both names interchangeably, using the appropriate product name based on the year the feature was introduced. For more information on the rebranding, see our website

Content Overview

Initial Troubleshooting

  • If the app is not accessible confirm that:
    • the app was saved and appears in the list of Flow Apps on FME Flow Web UI > Flow Apps > Manage <App type> Apps page
    • the app is active and hasn’t expired or been disabled
    • you are entering the correct URL to the app. The URL may change if your organization changes its FME Flow hostname
    • the FME Flow machine hosting the app is running
    • the FME Flow services are running on the machine hosting the app
    • You are on the same network as the FME Flow hosting the app. If the FME Flow is hosted on-premises behind a company firewall, then you must be on the same company network, directly or connected via VPN. The app will not be accessible via the internet in this scenario. 
  • If the app is still inaccessible, try checking your browser’s developer tools to see what errors are returned to the browser. In Google Chrome, the developer tools are accessed by pressing F12. Refresh the app web pages after opening developer tools and check the Network tab for any errors that may indicate why the app isn’t accessible.     
  • If the app is accessible but returning ‘Failed’ when you run it:
    • There are many Log Files that may help identify errors related to issues with jobs. Start by checking those listed below.
      • <FMEFlowSystemShare>\resources\logs\core\current\fmeserver.log
      • <FMEFlowSystemShare>\resources\logs\core\current\fmesharedresource.log
      • <FMEFlowSystemShare>\resources\logs\engine\current\*.log
  • Currently, in Automation Apps in FME 2022.2, the File manual parameter does not support temporary uploads. The File parameter allows end users to select a file from the FME Server Resources folder.

Common Issues 

“My app looks different between browsers on my mobile device.”

Google Chrome is recommended for the best FME Flow App experience. Please read Known Issue: FME Flow Apps will have a different appearance on various devices for more information.

“User Parameters are missing from my app’s form.”

In your Flow App settings, expand the Parameters section and confirm that “Show in App” is checked. If the parameter is not in the Parameter section at all, confirm it exists in your workspace and that it is a published parameter.

“My app has a file/URL parameter that is visible, but users don’t have the option to upload files. They can only browse for resources on FME Flow.” 

In your Flow App settings, ensure the setting ‘“User Can Upload” is enabled.

“There is no option to browse for resources or upload files for my published file/URL parameter. I only see a textbox.”

This is a known issue that occurs if a file/URL parameter has been set as Geodatabase under “Items to Select” in the parameter configuration. Leave Items to Select as Files (the default) and upload the geodatabase as a .zip file.

“I receive the error "There was and error uploading the file" when trying to upload files via my app”

Check your dataupload.log file found in resources\logs\service\current for errors. An EOFException error, like the one shown below, could indicate an incorrectly configured load balancer in a fault tolerant installation. Ensure that the load balancer is routing traffic between all FME Flow instances in the fault tolerant installation and not pointed at itself. Please see Installing for Fault Tolerance for more information.

Request failure, status 400, org.apache.commons.fileupload.FileUploadException:


“Why are users being asked to log in? What credentials are they supposed to enter?”

If “Require Authentication” is enabled, then users will be prompted to log in when trying to access the app URL. Ensure the necessary users and/or roles have been allowed access to the app. Users log in with the same method and credentials they use to log on to FME Flow. For example, their FME Flow username and password.

“I cannot grant an Active Directory (AD) group access to my app.”

This is a known issue. Each AD user needs to be added individually.

“When ‘Require Authentication’ is enabled, and a user signs in with Microsoft, they are redirected to the FME Flow home page instead of the app.”

This known issue was resolved in 2022.1, but occurs in earlier versions of FME Flow. If a Flow App (workspace or gallery) has ‘Require Authentication’ enabled and the allowed user was imported from Azure Active Directory (AD), then AD user needs to first log into FME Flow and then go to the app URL.

“I get an “Unauthorized request by user due to lack of proper permissions” error when I run my app.”

If your app uses database or web connections, the user running the app must have access to those connections. Please read FME Flow Connections Runtime Error: Unauthorized request by user due to lack of proper permissions for more information.

“When configuring an FME Flow App, the Show In App checkbox is missing for all parameters that are within a group box.”

This is a known issue. Move the File parameters outside of the group box.

“I cannot click OK to run my app.”
This known issue was resolved in 2022.1 but occurs in earlier versions of FME Server. This is likely because the workspace app contains a parameter that is required but is not visible and has no default value. Either set a default value or make the parameter visible. 
In the fixed versions of FME Server, users will be prompted to select a value for the parameter. Please see Known Issues in FME 2022.x.
"I receive an "Unhandled Exception" error when trying to save my FME Server App."
This is a known issue in 2021.2.6 and later that can occur when there is an optional parameter with no default value. FME Server may let you save the app with no default value once or twice before the error occurs. Try recreating the parameter or providing a default value.
 " I created a file manual parameter for my Automation app and the end user can't access the FME Flow Resources folder to select a file." 
This is a known issue with the lack of permissions for the Automation app token and is resolved in FME 2023.0 and newer. The workaround is to go to the Token Management page and grant Access and List permissions to the Resources' subfolders of choice. For example, the Data folder or a Network directory.

Are you still experiencing issues? 

Please consider posting to the FME Community Q&A if you are still experiencing issues that are not addressed in this article. There are also different support channels available.

Have ideas on how to improve this? 

You can add ideas or product suggestions to our Ideas Exchange.

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