Resolve "Property does not exist on type 'Vue'" error

I had the same problem but with exporting component. Some vs code snippets create template without necessary typo like this below

export default {
  data() {
    return {
      x: "something",
    };
  },
  methods: {
    rename(name: string) {
      this.x = name;
    },
    
  },
};

The problem was i did not add defineComponent() to export default. So should be

import { defineComponent } from "vue";

export default defineComponent({
  data() {
    return {
      x: "something",
    };
  },
  methods: {
    rename(name: string) {
      this.x = name;
    },
    
  },
});

Make sure you exporting component with defineComponent() function

you should make a declare for import *.vue file.

such as:

vue-file-import.d.ts

declare module "*.vue" {
   import Vue from "vue";
   export default Vue;
}

Adding another answer to bring together several things you may need to fix.

Ensure you include the ".vue" extension in the filename being imported

While both

import Competency from '../components/competency';

and

import Competency from '../components/competency.vue';

may compile successfully, the second one will help avoid the error appearing in some IDE's such as VS Code.

Add a shim typings file

As @May pointed out above, you need a file that imports and re-exports the type of "Vue". In @May's answer, it is named vue-file-import.d.ts, but elsewhere on the internet it is commonly called vue-shim.d.ts. Regardless of name, the content needed is the same:

// vue-file-import.d.ts

declare module "*.vue" {
   import Vue from "vue";
   export default Vue;
}

Try different locations for the shim file.

Originally I put it in /src. I found this had an odd effect. Sometimes it worked, i.e. the VS Code error messages disappeared; and other times it didn't, they reappeared. This happened dynamically as I moved around the project editing different files.

I later found the suggestion for a shim file of identical content, but to be placed in /typings. I tried this and it worked consistently. Other people seem quite happy with the /src location.