2019.3.0f6, TMP 2.0.1. Errors during fallback font asset atlas texture update

Hello! I'm ran into issue when fallback font atlas texture updating throws error:

ArgumentException: An item with the same key has already been added. Key: 0
System.Collections.Generic.Dictionary`2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) (at <437ba245d8404784b9fbab9b439ac908>:0)
System.Collections.Generic.Dictionary`2[TKey,TValue].Add (TKey key, TValue value) (at <437ba245d8404784b9fbab9b439ac908>:0)
TMPro.TMP_FontAsset.InitializeDictionaryLookupTables () (at Library/PackageCache/com.unity.textmeshpro@2.0.1/Scripts/Runtime/TMP_FontAsset.cs:589)

Also, after this error, i have error in play mode:
NullReferenceException: Object reference not set to an instance of an object
TMPro.TextMeshProUGUI.UpdateSDFScale (System.Single scaleDelta) (at Library/PackageCache/com.unity.textmeshpro@2.0.1/Scripts/Runtime/TMPro_UGUI_Private.cs:4264)

1. Save my new atlas
2. Right after step 1
3. After entering play mode, the following 170+ errors are identical

 

Full errors message

 

So, i changed this line (589 in TMP_FontAsset.cs in PackageCache) from

Code (CSharp):

1. m_FontFeatureTable.m_GlyphPairAdjustmentRecordLookupDictionary.Add(key, record);

to

Code (CSharp):

1. m_FontFeatureTable.m_GlyphPairAdjustmentRecordLookupDictionary[key] = record;

and after that it started working but i have to do this modification every time when cache updated.

Perhaps this information will be useful.