Power Automate error - The JSON value could not be converted to System.String

Hi all - absolute newbie here, so I'm definitely doing something dopey. I've got a simple process that creates a ppt with integrated Power BI visuals. When testing the process it works as expected, but when adding a PowerAutomate to create the ppt on Sharepoint, the process fails with the below error:

The flow I'm using is:

And the ppt doesn't contain any text, just a BI visual. Any help really appreciated, thank you!

Hi @jfox,

It's an error from power Automate itself. When it receives the process output, it doesn't like some values.

Could you share more details about the process settings and probably share the template itself?

How do you initially start the process? What values are sent to the template?

Best regards,
Petr
Plumsail team