Unrecognized partition found, index 1 disk layout validation failed

The error Unrecognized partition found, index 1 disk layout validation failed occurs while converting MBR to GPT. This article lists the reasons and fixes for this error.
Ars Technica

Expanding GPT/Dynamic disks

I've got a system that I'm upgrading the disk array (3Ware RAID controller) on. Both the new and old arrays are >2TB, so they're GPT, instead of MBR. In order to minimize down-time, I'll be setting up ...
Ars Technica

Converting an MBR disk to a GPT disk?

Does anyone know if it's safe to run the Windows 10 "mbr2gpt.exe" tool on a (non-OS) disk in Server 2008 R2? If so, is the process reasonably quick? (This is an almost completely full, 2.0 TB disk.) ...
Forbes

GPT-5’s System Prompt Just Leaked. Here’s What We Learned

GPT-5’s system prompt just leaked to Github, showing what OpenAI wants ChatGPT to say, do, remember … and not do. Unsurprisingly, GPT-5 isn’t allowed to reproduce song lyrics or any other copyrighted ...