I've seen other posts regarding upgrades hanging at 90%, and errors in the log regarding schemas (my specific error shown below), but I'm unable to find any resolution. My question is, considering that 6.2.6 is only a bug fix for the cpu thrashing issue, can I safely set the umbraco version to 6.2.6 and ignore the database upgrade process? Isn't it ultimately just a fix in one of the client dlls? I've tried this on a test instance and everything appears to work fine.

For info, the specific error in my log file is attached below:

2016-05-04 11:51:50,996 [29] INFO Umbraco.Core.DatabaseContext - [Thread 38] Database configuration failed with the following error and stack trace: This SqlTransaction has completed; it is no longer usable. at System.Data.SqlClient.SqlTransaction.ZombieCheck() at System.Data.SqlClient.SqlTransaction.Rollback() at Umbraco.Core.Persistence.Database.CleanupTransaction() at Umbraco.Core.Services.MediaService.RebuildXmlStructures(Int32[] contentTypeIds) at Umbraco.Core.Events.TypedEventHandler`2.Invoke(TSender sender, TEventArgs e) at Umbraco.Core.Persistence.Migrations.MigrationRunner.Execute(Database database, DatabaseProviders databaseProvider, Boolean isUpgrade) at Umbraco.Core.DatabaseContext.UpgradeSchemaAndData() 2016-05-04 11:51:51,011 [29] INFO Umbraco.Core.DatabaseContext - [Thread 38] The database schema validation produced the following summary: The following tables were found in the database, but are not in the current schema: UFFormStates,approvalsContent,UFRecordsXml,UFRecordDataInteger,UFRecordDataLongString,ConciergeLockUnLock,UFRecordFields,UFDataSourceMappings,databasefirewallrules,subscriptionQueue,UFWorkflows,UserGroupPermissions_UserType2NodePermission,UFRecords,UFFields,UFRecordDataString,UCUserSettings,UFRecordDataDateTime,UFWorkflowsToForms,UFFieldConditionRules,UFUserSecurity,UFPrevalues,UFPrevalueSources,UFWorkflowExecutionStates,UFDataSources,UFForms,UFPrevalueSourceSettings,UFFieldConditions,UFFieldSettings,UFFieldsets,UFRecordDataBit,UFUserFormSecurity,UFPages,UFSettings

The following columns were found in the database, but are not in the current schema: UFFormStates,State,approvalsContent,Id,approvalsContent,ContentId,approvalsContent,UserId,approvalsContent,Version,approvalsContent,Date,approvalsContent,Deletion,approvalsContent,Move,approvalsContent,OldParent,approvalsContent,NewParent,approvalsContent,CheckedOutBy,approvalsContent,Cormac,approvalsContent,MemberId,UFRecordsXml,id,UFRecordsXml,Form,UFRecordsXml,xml,UFRecordsXml,created,UFRecordsXml,Page,UFRecordDataInteger,Key,UFRecordDataInteger,Value,UFRecordDataLongString,Key,UFRecordDataLongString,Value,ConciergeLockUnLock,nodeId,ConciergeLockUnLock,userId,ConciergeLockUnLock,status,ConciergeLockUnLock,comment,ConciergeLockUnLock,DateStamp,ConciergeLockUnLock,ticketId,UFRecordFields,Key,UFRecordFields,Field,UFRecordFields,Record,UFRecordFields,DataType,UFDataSourceMappings,DataSource,UFDataSourceMappings,DataSourceField,UFDataSourceMappings,Form,UFDataSourceMappings,PrevalueTable,UFDataSourceMappings,PrevalueKeyField,UFDataSourceMappings,PrevalueValueField,UFDataSourceMappings,DataType,UFDataSourceMappings,DefaultValue,databasefirewallrules,id,databasefirewallrules,name,databasefirewallrules,startipaddress,databasefirewallrules,endipaddress,databasefirewallrules,createdate,databasefirewallrules,modifydate,subscriptionQueue,Id,subscriptionQueue,ContentId,subscriptionQueue,UserId,subscriptionQueue,PublishDate,subscriptionQueue,Version,subscriptionQueue,Subscribers,subscriptionQueue,TimeToSend,subscriptionQueue,Template,subscriptionQueue,Pending,subscriptionQueue,Message,UFWorkflows,Id,UFWorkflows,Name,UFWorkflows,Type,UFWorkflows,SortOrder,UFWorkflows,Active,UFWorkflows,Form,UFWorkflows,ExecutesOn,UserGroupPermissionsUserType2NodePermission,userTypeId,UserGroupPermissionsUserType2NodePermission,nodeId,UserGroupPermissions_UserType2NodePermission,permission,UFRecords,Id,UFRecords,Form,UFRecords,Created,UFRecords,Updated,UFRecords,State,UFRecords,currentPage,UFRecords,umbracoPageId,UFRecords,IP,UFRecords,MemberKey,UFFields,Id,UFFields,Fieldset,UFFields,Fieldtype,UFFields,PreValueProvider,UFFields,RegEx,UFFields,Mandatory,UFFields,SortOrder,UFFields,Caption,UFFields,DataSourceField,UFFields,ToolTip,UFFields,DefaultValue,UFFields,RequiredErrorMessage,UFFields,InvalidErrorMessage,UFRecordDataString,Key,UFRecordDataString,Value,UCUserSettings,User,UCUserSettings,Key,UCUserSettings,Value,UFRecordDataDateTime,Key,UFRecordDataDateTime,Value,UFWorkflowsToForms,Workflow,UFWorkflowsToForms,Form,UFFieldConditionRules,Id,UFFieldConditionRules,FieldCondition,UFFieldConditionRules,Field,UFFieldConditionRules,Operator,UFFieldConditionRules,Value,UFUserSecurity,User,UFUserSecurity,ManageDataSources,UFUserSecurity,ManagePreValueSources,UFUserSecurity,ManageWorkflows,UFUserSecurity,ManageForms,UFPrevalues,Id,UFPrevalues,Field,UFPrevalues,Value,UFPrevalues,SortOrder,UFPrevalueSources,Id,UFPrevalueSources,Name,UFPrevalueSources,Type,UFWorkflowExecutionStates,Workflow,UFWorkflowExecutionStates,State,UFWorkflowExecutionStates,Form,UFDataSources,Id,UFDataSources,Type,UFDataSources,Name,UFForms,Id,UFForms,Name,UFForms,Created,UFForms,ManualApproval,UFForms,GotoPageOnSubmit,UFForms,MessageOnSubmit,UFForms,DataSource,UFForms,ShowValidationSummary,UFForms,HideFieldValidation,UFForms,RequiredErrorMessage,UFForms,InvalidErrorMessage,UFForms,FieldIndicationType,UFForms,Indicator,UFForms,Archived,UFForms,StoreRecordsLocally,UFForms,DisableDefaultStylesheet,UFForms,Entries,UFForms,Views,UFPrevalueSourceSettings,PrevalueProvider,UFPrevalueSourceSettings,Key,UFPrevalueSourceSettings,Value,UFFieldConditions,Id,UFFieldConditions,Field,UFFieldConditions,Enabled,UFFieldConditions,ActionType,UFFieldConditions,LogicType,UFFieldSettings,Field,UFFieldSettings,Key,UFFieldSettings,Value,UFFieldsets,Id,UFFieldsets,Page,UFFieldsets,SortOrder,UFFieldsets,Caption,UFRecordDataBit,Key,UFRecordDataBit,Value,UFUserFormSecurity,User,UFUserFormSecurity,Form,UFUserFormSecurity,HasAccess,UFUserFormSecurity,SecurityType,UFUserFormSecurity,AllowInEditor,UFPages,Id,UFPages,Form,UFPages,SortOrder,UFPages,Caption,UFSettings,Id,UFSettings,Key,UFSettings,Value

The following constraints (Primary Keys, Foreign Keys and Indexes) were found in the database, but are not in the current schema: FKUFDataSourceMappingsUFDataSources,FKUFDataSourceMappingsUFForms,FKUFFieldUFFieldsets,FKUFFieldConditionRulesUFFieldConditions,FKUFFieldConditionRulesUFFields,FKUFFieldConditionsUFFields,FKUFFieldsetsUFPages,FKUFFieldSettingsUFFields,FKUFFormsUFDataSources,FKUFPagesUFForms,FKUFPrevaluesUFFields,FKUFPrevalueSettingsUFPrevalueProviders,FKUFRecordDataBitUFRecordFields,FKUFRecordDataDateTimeUFRecordFields,FKUFRecordDataIntegerUFRecordFields,FKUFRecordDataLongStringUFRecordFields,FKUFRecordDataStringUFRecordFields,FKUFRecordFieldsUFFields,FKUFRecordFieldsUFRecords,FKUFRecordsUFForms,FKUFRecordsXmlUFForms,FKUFUserFormSecurityUFForms,FKUFWorkflowExecutionStatesUFFormStates,FKUFWorkflowsUFForms,PK[UserGroupPermissionsUserType2NodePermission,PKapprovalsContent,PKcmsPreviewXml,PKConciergeLockUnLock,PKsubscriptionQueue,PKUCUserSettings,PKUFDataSourceMappings,PKUFDataSources,PKUFField,PKUFFieldConditionRules,PKUFFieldConditions,PKUFFieldsets,PKUFForms,PKUFFormStates,PKUFPages,PKUFPrevalueProviders,PKUFPrevalues,PKUFPrevalueSettings,PKUFRecordFields,PKUFRecords,PKUFRecordsXml,PKUFSettings,PKUFUserFormSecurity,PKUFUserSecurity,PKUFWorkflowExecutionStates,PKUFWorkflows,PKUFWorkflowsToForms,PKcmsContentPreviewXml,IXumbracoNodeTrashed,IXumbracoNodeParentId,IXumbracoNodeObjectType,IXcmsTemplatenodeId,IXcmsContent,IXcmsContentVersionContentId,IXcmsContentVersionVersionId,IXcmsDocument,IXcmsDocumentpublished,IXcmsDocumentnewest,IXcmsContentType,IXcmsContentTypeicon,IXcmsDataTypenodeId,IXcmsDictionaryid,IXumbracoLanguagelanguageISOCode,IXumbracoLog,IXcmsPropertyData,IXcmsPropertyData1,IXcmsPropertyData2,IXcmsPropertyData3,IXumbracoUserLoginsIndex,IXumbracoUseruserLogin,IXcmsTaskTypealias,IXcomputerName,IXumbracoServerisActive

The following indexes were found in the database, but are not in the current schema: dtaindexcmsContent8965578478K2K13,dtaindexcmsContentVersion81157579162K2,dtaindexcmsContentVersion81157579162K3K1K2K45,dtaindexcmsDocument81093578934K2K11K6K413578910,dtaindexcmsPropertyData81797581442K2K3K1K4567,PK,dtaindexumbracoNode8485576768K10K1K7234568911