Why does my app not work properly on Android Lollipop?

Question

I've made this very simple app with just a RecyclerView and a dialog that pops up prompting you to enter info you want to save in a SQLite database. It's not really a serious project, but the app for some reason crashes on Lollipop and gives InlfateException: Binary XML file line #N: Error inflating class EditText when pressing the button that opens the dialog for the user to insert information. I've checked absolutely everywhere for this and I haven't found solution for it. I have had apps not work properly on Lollipop before and I wasn't able to fix it. I have found some other StackOverflow posts about it and they say that it's a gradle problem, but they were really outdated so they were no use to me. App works fine on anything above Lollipop. Tested on both a physical and a virtual device

Edit:

Dialog xml code:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000"
    android:padding="16dp">

    <EditText
        android:id="@+id/editWord"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/custom_et"
        android:fontFamily="@font/sf_light"
        android:hint="Word"
        android:inputType="text"
        android:padding="10dp"
        android:textColorHint="#474747" />

    <EditText
        android:id="@+id/editWordDesc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editWord"
        android:layout_marginTop="20dp"
        android:background="@drawable/custom_et"
        android:fontFamily="@font/sf_light"
        android:hint="Word Meaning"
        android:inputType="text"
        android:padding="10dp"
        android:textColorHint="#474747" />
</RelativeLayout>

Main activity XML code:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:background="#000"
    android:padding="10dp">

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:backgroundTint="#232323"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        app:borderWidth="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:src="@drawable/ic_add"
        app:layout_constraintVertical_bias="1.0" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

Edit 2: InlfateException: Binary XML file line #9: Error inflating class EditText for the dialog layout

Edit 3: the problem was with the custom_et file and removing it fixed the problem.