It is recommended that you use the 2019.4.29f1 version of Unity when creating STYLY scenes via Unity.
Unity 2019.4.29f1 version must also be used when utilizing PlayMaker.
If you install PlayMaker with Unity 2019.4.29f1 version or later (e.g. 2021.2022 version) and then try to install PlayMaker again with Unity 2019.4.29f1 version, you will see the following image message and PlayMaker will not install.
This article explains how to resolve this issue.
This issue is caused by installing PlayMaker on a version of Unity higher than 2019.4.29f1, which causes the Unitypackage itself to be overwritten by the higher version of Unity.
You can solve this problem by deleting the already downloaded PlayMaker UnityPackage and installing PlayMaler again.
Delete the Playmaker.unitypackage stored in the file path.
Please check the file path as it differs depending on your OS.
C:Users%USERNAME%AppDataRoamingUnityAsset Store-5.xHutong Games LLC
~/Library/Unity/Asset Store-5.x/Hutong Games LLC
Then launch Unity on 2019.4.29f1 and download and import PlayMaker again.
This will install PlayMaker correctly.