I am just getting started with AI in DEVONthink 4. I created an account at Perplexity, obtained an API key, and entered the info into the AI pane of DT Preferences. Using the Chat window, I submitted some simple prompts. I always get this response: “The data couldn’t be read because it isn’t in the correct format.” I am using my work computer with VPN off, but it’s possible that a security layer is blocking communication with perplexity.ai.
Which model did you use? I just tested this and everything seems to be working as expected. Anyway, please choose Help > Report Bug while pressing the Alt modifier key and send the result to cgrunenberg - at - devon-technologies.com - thanks!
I started with Sonar Reasoning Pro. Then moved to Sonar Reasoning and then to Sonar.
Come now, really, the “Alt” key?!
Option 
Alt is not entirely uncommon or unknown in Mac circles.