Are there limitations for the Merge PDF action in Microsoft Power Automate(old name: Microsoft Flow)?


I am testing the Merge PDF action in Microsoft Power Automate and ran in some issues.

"message": "The response is not in a JSON format.",
"innerError"[:.......]404 - File or directory not found.\r\n

The resource you are looking for might have been removed, had its name changed, or is temporarily unavailable.[.......]\r\n"

Here is my Flow :

So everytime I try to merge more than 50 PDF's I get the Error. When i merge the 50 PDF's the outcoming Document is like 21.4MB. (I didn't changed the Flow)

My goal is to Merge multiple Files, which are stored on a Sharepoint Online, (Serial Letters) to one PDF.
In the worst case there would be arounf 650 PDF's that have to be merged.

So my question is, are there any limitations of the amount of PDF's or the file size of the result PDF for the Merge action in Power Automate/Flow ? (I didn't found the answer in the documentation)

Best regards,
Christian Düster

Hello @cDue,

Actually we don't have the limitations, it might work a bit longer though in case of merging this number of documents, but actually should be completed. Could you try the action again and let me know if it still reports the failure when you merging 50+ PDFs?

Best regards,
Petr Bushuev
Plumsail team

Hello @Petr,

As you told me I tryed again with 51 documents and the same Error appeared. After this I did the same but with 50 documents (deleted one on the Sharepoint site) and it succeeded.

Best regards,
Christan Düster