Error Inflating Class <unknown>

When running my app, I receive the following message:
Java.Lang.RuntimeException
Binary XML file line #1 in com.companyname.illusionexperimental:layout/activity_main: Binary XML file line #1 in com.companyname.illusionexperimental:layout/experimentallayout: Error inflating class <unknown>
experimentallayout is an XML layout file included in activity_main as follows:
<include android:visibility="visible" android:id="@+id/incExperimentalLayout" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_column="0" android:layout_row="0" layout="@layout/experimentallayout"/>
Both activity_main and ExperimentalLayout.xml have the following as line #1 (the line stated in the error message):
<?xml version="1.0" encoding="utf-8"?>
The Designer in Visual Studio 2022 displays the files without any problem, and compiles without any problem. How can I determine what the problem is?