Cannot Build Android When Package Name Not Follow 'com.company.product' Convention Unity 2021.3

My game package name current format is 'company.product' and its already published, built using Unity 2020. Now I am about to switch to Unity 2021.3, but in Unity 2021 the package name must use format 'com.company.product'. It is imposible to change package name since its already published. Is there any solution to build my game in Unity 2021?

In Unity 2021 I cannot build


Thanks

 

Thanks for the solution, I will try.

Yes it is already published to Google Play, that the reason I can't change the package name.

Thanks

 

Actually, Unity Editor is trying to force an incorrect guideline and therefore needs to be fixed in future Unity versions. (Reported as a bug.)
The actual guidelines are the following:

• It must have at least two segments (one or more dots).
• Each segment must start with a letter.
• All characters must be alphanumeric or an underscore [a-zA-Z0-9_].

(source: https://developer.android.com/studio/build/configure-app-module )