[▲ Vercel Community](/) · [Categories](/categories) · [Latest](/latest) · [Top](/top) · [Live](/live) [v0](/c/v0/59) # V0 can not solve the error undefined (reading 'toLowerCase') 10 views · 0 likes · 3 posts Huda (@habdulqader-6640) · 2026-02-24 Suddenly, my project stopped working. I did not send any new prompt; it was working, and then the following error is displayed “Unhandled promise rejection: TypeError: Cannot read properties of undefined (reading 'toLowerCase')“, I tried tp solve it multiple times and used a lot of the credits and still not working. Please solve this ASAP Pauline P. Narvas (@pawlean) · 2026-02-24 Hey, Huda! Welcome to the Vercel Community :waving_hand: What have you tried so far? It's difficult to give you more specific guidance without any chat links, or examples. I recommend going through: https://community.vercel.com/t/how-to-get-good-answers/158 Huda (@habdulqader-6640) · 2026-02-24 I searched the v0 community already, here the project link [https://v0.app/chat/package-creation-page-qnkPQjD0AK1](https://v0.app/chat/package-creation-page-qnkPQjD0AK1), please review it and share a new link with the working project.