DocType import error

[yavorsky-vl]

Describe the bug
When importing one of the documents, I get an error:
Import Fail: Object reference not set to an instance of an object.
It looks like one of the operations exceeds the timeout.
I have caught look in database:
Directly Blocked Transactions:
Blocking SQL Statement
SELECT [umbracoDocument].[nodeId] AS [NodeId], [umbracoDocument].[published] AS [Published], [umbracoDocument].[edited] AS [Edited] , [umbracoContent].[contentTypeId] AS [ContentDto__ContentTypeId], [umbracoContent].[nodeId] AS [ContentDto__NodeId] , [umbracoNode].[id] AS [ContentDto__NodeDto__NodeId], [umbracoNode].[uniqueId] AS [ContentDto__NodeDto__UniqueId], [umbracoNode].[parentId] AS [ContentDto__NodeDto__ParentId], [umbracoNode].[level] AS [ContentDto__NodeDto__Level], [umbracoNode].[path] AS [ContentDto__NodeDto__Path], [umbracoNode].[sortOrder] AS [ContentDto__NodeDto__SortOrder], [umbracoNode].[trashed] AS [ContentDto__NodeDto__Trashed], [umbracoNode].[nodeUser] AS [ContentDto__NodeDto__UserId], [umbracoNode].[text] AS [ContentDto__NodeDto__Text], [umbracoNode].[nodeObjectType] AS [ContentDto__NodeDto__NodeObjectType], [umbracoNode].[createDate] AS [ContentDto__NodeDto__CreateDate] , [umbracoDocumentVersion].[id] AS [DocumentVersionDto__Id], [umbracoDocumentVersion].[templateId] AS [DocumentVersionDto__TemplateId], [umbracoDocumentVersion].[published] AS [DocumentVersionDto__Published] , [umbracoContentVersion].[id] AS [DocumentVersionDto__ContentVersionDto__Id], [umbracoContentVersion].[text] AS [DocumentVersionDto__ContentVersionDto__Text], [umbracoContentVersion].[versionDate] AS [DocumentVersionDto__ContentVersionDto__VersionDate], [umbracoContentVersion].[nodeId] AS [DocumentVersionDto__ContentVersionDto__NodeId], [umbracoContentVersion].[userId] AS [DocumentVersionDto__ContentVersionDto__UserId], [umbracoContentVersion].[current] AS [DocumentVersionDto__ContentVersionDto__Current] , [pdv].[id] AS [PublishedVersionDto__Id], [pdv].[templateId] AS [PublishedVersionDto__TemplateId], [pdv].[published] AS [PublishedVersionDto__Published] , [pcv].[id] AS [PublishedVersionDto__ContentVersionDto__Id], [pcv].[text] AS [PublishedVersionDto__ContentVersionDto__Text], [pcv].[versionDate] AS [PublishedVersionDto__ContentVersionDto__VersionDate], [pcv].[nodeId] AS [PublishedVersionDto__ContentVersionDto__NodeId], [pcv].[userId] AS [PublishedVersionDto__ContentVersionDto__UserId], [pcv].[current] AS [PublishedVersionDto__ContentVersionDto__Current] , COALESCE([ccv].[name],[umbracoNode].[text]) AS variantName FROM [umbracoDocument] INNER JOIN [umbracoContent] ON [umbracoDocument].[nodeId] = [umbracoContent].[nodeId] INNER JOIN [umbracoNode] ON [umbracoContent].[nodeId] = [umbracoNode].[id] INNER JOIN [umbracoContentVersion] ON ([umbracoDocument].[nodeId] = [umbracoContentVersion].[nodeId]) INNER JOIN [umbracoDocumentVersion] ON ([umbracoContentVersion].[id] = [umbracoDocumentVersion].[id]) LEFT JOIN [umbracoContentVersion] [pcv] INNER JOIN [umbracoDocumentVersion] [pdv] ON (([pcv].[id] = [pdv].[id]) AND [pdv].[published] = @0) ON ([umbracoDocument].[nodeId] = [pcv].[nodeId]) LEFT JOIN [umbracoContentVersionCultureVariation] [ccv] INNER JOIN [umbracoLanguage] [lang] ON (([ccv].[languageId] = [lang].[id]) AND ([lang].[languageISOCode] = @1)) ON ([umbracoContentVersion].[id] = [ccv].[versionId]) WHERE (([umbracoNode].[nodeObjectType] = @2)) AND ([umbracoContentVersion].[current] = @3) AND ([umbracoContent].[contentTypeId] IN (@4)) ORDER BY [ContentDto__NodeDto__Path] , [ContentDto__NodeDto__NodeId] OFFSET @5 ROWS FETCH NEXT @6 ROWS ONL
Blocked SQL Statement
UPDATE umbracoLock SET value = (CASE WHEN (value=1) THEN -1 ELSE 1 END) WHERE id=@