For me, copying the files from the newly generated strapi environment was not sufficient. When I started the strapi after following the guide,
I got the following error:
```
/home/xxx/Dev/Projects/xxx/server/node_modules/mongodb/lib/mongo_client.js:804
throw err;
^
TypeError: Cannot read property 'globalId' of undefined
```
I guess this was the case because strapi-mongoose was not upgraded. I don't know if I'm blind or did not read the migration guide carefully enough, but for me a `npm install` at the end did the trick and upgraded it.
Maybe this is helpful for you