com.unity.textmeshpro@1.3.0 com.unity.textmeshpro@2.0.0 error lỗi unity up lên 2019.2

I Had a problem with in Unity 2019.1.0f2 with the Bolt Plugin. I used to following steps to get it running again:

ERROR
Library\PackageCache\com.unity.textmeshpro@2.0.0\Scripts\Editor\TMP_PackageUtilities.cs(310,17): error CS0433: The type 'Task' exists in both 'System.Threading, Version=1.0.2856.102, Culture=neutral, PublicKeyToken=31bf3856ad364e35' and 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'

FIX
1. Go to Window->Package Manager
2. TextMesh Pro (Version 2.0.0 will be installed)
3. Click on the arrow > on the left to see all the available versions.
4. Update TextMesh Pro to 1.3.0 (same version as in Unity 2018.3.12f1)

*** Let the compiler finish and you should see the error clearing from the console ***