Symptoms
Assume that you use SQL Server 2019, you may notice that the data masking of user-defined functions (UDF) may result in crashes.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Resolution
This issue is fixed in the following cumulative update for SQL Server:
About cumulative updates for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Workaround
To work around the issue, you can turn off the trace flag 203 (TF203). This prevents the crashes, but could lead to the data masking not being properly applied to queries which use user-defined functions.
References
Learn about the terminology that Microsoft uses to describe software updates.