Unable to upload an application to Web AppBuilder for ArcGIS (Developer Edition)

Description

In Web AppBuilder for ArcGIS (Developer Edition), there are two possible ways to upload an application: by importing via an ArcGIS Online account or from the user's machine.

Cause

There are two possible causes for this issue:

• ​​​Scenario 1: Uploading an application that is created using another platform  
  • When an application is created using applications other than Web AppBuilder for ArcGIS and uploaded to Web AppBuilder for ArcGIS, the folder format may not follow the required format.
• Scenario 2: Uploading an application after editing
  • When an application created using Web AppBuilder for ArcGIS is downloaded and edited, the folder structure may not use the required format. This may happen when the user performed changes to the application, such as adding custom widgets (which involves JavaScript or CSS files).

Solution or Workaround

1. Create a new application by clicking Create New, and select the desired type of application.

2. Provide the necessary name and description for the application.
3. Download the newly created application on the home page of Web AppBuilder for ArcGIS.

4. Perform the necessary edits and re-upload the application to Web AppBuilder for ArcGIS. This maintains the folder architecture. 

1. Follow steps 1 and 2 in Scenario 1. 
2. Open the newly created application, and note the ID of the application at the end of the browser address bar. The following image shows an example of how the application link appears. In the example, the ID for the newly created app is 2.

3. Download the newly created application.
4. Open the application folder in the installed folder of Web AppBuilder for ArcGIS. The following is an example of the folder location.

[Instal_DIR]\server\[App_Name]

5. Open the newly created app folder, and copy all the folders from the old application folder, which contains the necessary edits performed.
6. Paste the folders into the newly created application folder. Allow the necessary permissions to replace the files and overwrite the files if Windows prompts are returned.
7. Refresh the browser. The edited application is now uploaded without any error message.