This usually happens if the Portable folder was moved, renamed, or re-downloaded, which can reset the local activation data on the USB. Plug in the same USB stick, open Unregistered → here, and enter your license key again while you’re online.
To avoid repeats, keep the folder structure unchanged, use the same USB across PCs, and make sure your system time is correct (Windows time sync) during activation.
The Portable Edition asks me to activate again.
Helpful?