title: How do I fix Unity textmeshpro error after updating 2018.1 to 2018.3?
body: <p>After updating from unity 2018.1 to Unity 2018.3, there is a bunch of error messages about text mesh pro. Here are the error messages
  /Users/administrator/Dropbox/Sebastian/home/coding/Unity/Experimental Project/Library/PackageCache/com.unity.textmeshpro@1.3.0/Scripts/Runtime/TMP_Text.cs(4929,40): error CS0121: The call is ambiguous between the following methods or properties: <code>TMPro.TMPro_ExtensionMethods.Multiply(this UnityEngine.Color32, UnityEngine.Color32)' and</code>TMPro.TMPro_ExtensionMethods.Multiply(this UnityEngine.Color32, UnityEngine.Color32)'</p>
  
  <p>/Users/administrator/Dropbox/Sebastian/home/coding/Unity/Experimental Project/Library/PackageCache/com.unity.textmeshpro@1.3.0/Scripts/Runtime/TMPro_Private.cs(3552,92): error CS0121: The call is ambiguous between the following methods or properties: <code>TMPro.TMPro_ExtensionMethods.Compare(this UnityEngine.Color32, UnityEngine.Color32)' and</code>TMPro.TMPro_ExtensionMethods.Compare(this UnityEngine.Color32, UnityEngine.Color32)'</p>
  
  <p>Multiple plugins with the same name 'tmpro_plugin' (found at 'Packages/com.unity.textmeshpro/Plugins/64 Bit Plugins/TMPro_Plugin.bundle' and 'Assets/Downloaded Assets/TextMesh Pro/Plugins/64 Bit Plugins/TMPro_Plugin.bundle'). That means one or more plugins are set to be compatible with Editor. Only one plugin at the time can be used by Editor.</p>