Power Platform Community Forum Thread Details

I am uploading an Excel file from Power Apps using an Attachments control and passing it to a Power Automate flow (Power Apps V2). In the flow, I try to create the file in a SharePoint document library using triggerBody()['file']['contentBytes'], but the flow fails saying the file property cannot be selected. Older or duplicated flows work, but newly created flows fail. I need the correct approach to upload Excel from Power Apps, save it to SharePoint, and then read the Excel data.

powerapp:

testcreateitem.Run(
{
ContentBytes: First(DataCardValue11_1.Attachments).Value,
name: First(DataCardValue11_1.Attachments).Name
 
}
)
 
Error
Action 'Create_file' failed
Unable to process template language expressions in action 'Create_file' inputs at line '0' and column '0': 'The template language expression 'triggerBody()['file']['contentBytes']' cannot be evaluated because property 'file' cannot be selected. Please see https://aka.ms/logicexpressions for usage details.'.

Categories:

Building flows

Using flows

Your flow is looking for triggerBody()? ['file']['contentBytes'], but the Power Apps (V2) trigger is not giving you a file object named file. Older templates did. Newer ones often expose the inputs at the root, or under a different parameter name, so “file” cannot be selected.

Fix pattern

In Power Apps, pass two plain parameters Use the attachment’s Name and Value.

Power Apps test create item. Run(First(DataCardValue11_1.Attachments). Name, First (DataCardValue11_1.Attachments). Value)

In Power Automate, change the trigger to match the Power Apps (V2) trigger Add two inputs:

FileName (Text)
FileContent (File) or Text (base64)

If the trigger input type supports File:

Map FileContent directly from the Power Apps parameter.
In Create file, use: File Name = triggerBody()? ['FileName'] File Content = triggerBody()? ['FileContent']

If the trigger input is Text (base64):

Create file expects binary, so decode: File Content = base64ToBinary(triggerBody()? ['FileContent'])

Stop using triggerBody()? ['file'] paths In the Create file, pick the dynamic content tokens from the trigger input fields, or refer to triggerBody(). ['FileName'].triggerBody()? ['FileContent']
Validate what the trigger sends. Run once. Open the trigger step and show raw outputs. You will see the real JSON shape. Use those exact property names in expressions.

Common gotchas

Do not pass First(...). Value as ContentBytes. Pass it as the file content parameter, then decode only if your trigger treats it as text.
For large Excel files, the Power Apps to Flow payload size can break. If the file is big, upload it to SharePoint from the app (or use a chunked approach), then pass the SharePoint file identifier to the flow.

Working on an end-to-end approach for “upload, then read Excel” A) Power Apps sends file name + file content B) Flow creates the file in SharePoint. C) Flow uses Excel Online actions on the created file (Get tables, List rows), using the file identifier/path from Create file output, not a hardcoded path