In-App Purchases stopped working after updating project

I’m using the Purchaser script, which i got from there: Unity IAP - Unity Learn
It had been working perfectly, before I updated Unity to 2019.1.1f1. After update, I had to link my project again, I also updated the IAP module. Now the IAPs don’t work, the OnInitialized(..) function is never called. Automatically initialize Unity Purchasing is disabled. What’s wrong?

I had a similar problem. After trying many different things, what finally worked for me was to create a new project in v2018 import and update IAP, then copy the UnityChannel and UnityPurchasing from this projects plugins directory to the project that was having problems.

After doing this, my IAPs started to work again.

Hope this helps,