In Vue.js, custom event emission can be tricky due to its component-based architecture. Here are some common problems and ways to handle them:

1. Emit events with this.$emit() method in child components: Make sure that you are emitting the correct event name with $emit(). Also, make sure that the event name is consistent across all components.

Example:

<!-- Child component -->
<template>
  <button @click="handleClick">Click me</button>
</template>

<script>
export default {
  methods: {
    handleClick() {
      this.$emit('child-event', 'data');
    }
  }
}
</script>

In the parent component, you can listen to this event with @ symbol:

Example:

<!-- Parent component -->
<template>
  <ChildComponent @child-event="onChildEvent" />
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  methods: {
    onChildEvent(data) {
      console.log('Received data:', data);
    }
  },
  components: {
    ChildComponent
  }
}
</script>

2. Emit events with this.$emit() method in parent components: In the parent component, you can use v-on:eventName="handleEvent" to listen to an event that was emitted by a child component.

Example:

<!-- Parent component -->
<template>
  <ChildComponent @child-event="onChildEvent" />
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  methods: {
    onChildEvent(data) {
      console.log('Received data:', data);
    }
  },
  components: {
    ChildComponent
  }
}
</script>

3. Use v-model for two-way data binding with custom events in child components: If you want to create a component that can be used as input or output fields, use v-model instead of emitting custom events.

Example:

<!-- Child component -->
<template>
  <input type="text" v-model="value" />
</template>

<script>
export default {
  data() {
    return {
      value: ''
    }
  },
  props: ['value']
}
</script>

In the parent component, you can use v-model to bind the input field of this child component.

Example:

<!-- Parent component -->
<template>
  <ChildComponent v-model="inputValue" />
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  data() {
    return {
      inputValue: ''
    }
  },
  components: {
    ChildComponent
  }
}
</script>