Hey, without making any code changes or updates, this week "Error: NextRouter was not mounted. https://nextjs.org/docs/messages/next-router-not-mounted" started showing up on any page that uses plasmic.
Inside the pages/ directory this error is minor, as it continues on and renders the component normally, and Next.js handles prerendering so it still outputs statically, however, inside the app/ directory this error breaks the entire page, and if building, causes the build to fail. This includes when redeploying previously successful commits in vercel.
Minimum reproduction steps:
Create a “Blank Project” template
run “npx create-plasmic-app”, choose Next.js, the app/ directory (as the issue is more obvious there), and use the new project
cd into the created folder and run “npm run build”
See errors in the output.
Searching the slack I see a few people have had the same problem starting at the same time, but only buried in new replies to month old threads and nothing top level like this.