Reimport all, showing error....

HI,
My Unity version is 2019.2.21f and Unity IAP version is 1.23.1
I made empty project, and setup Unity IAP.
And when assets reimport all, showing error message.
“Error: Could not load signature of UnityEditor.Purchasing.GooglePlayProductCatalogExporter:productTypeString due to: Could not load file or assembly ‘UnityEngine.Purchasing, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null’ or one of its dependencies. assembly:UnityEngine.Purchasing, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null type: member:(null) signature:”

Restart Unity3d, error message not showing.Is this not serious problem?

I believe this is not a serious problem, you can re-import the IAP plugin.

You mention a reimport, did the first import fail? What version of the purchasing package are you showing in Package Manager? IAP requires both the Asset package and the Package Manager component.

The iap version of Package Manager is 2.0.6.
After executing Unity-[Asset]-[reimport all], an error is displayed every time.
In fact, after updating the existing project to unity 2019.2.21f, the above problem occurred, and when I tested it as an empty project, the same problem occurred.
However, on Android devices, test ordering works fine without problems.

Got it, then likely as Sam mentioned.