After upgrade to version 6.6 an error "Error converting data type nvarchar to bigint" on POS

After upgrade to version 6.6 an error "Error converting data type nvarchar to bigint" on POS

Environment: 

iVend 6.6

Problem Statement:

After upgrade I find the mentioned error when printing the Sales Transaction. How can this be fixed?
<Version>6.6.7989.24759</Version>
<Category>ERROR</Category>
<Time>09:32:37 am</Time>
<Message>Error converting data type nvarchar to bigint.</Message>
<ExceptionInfo>
<Type>System.Data.SqlClient.SqlException</Type>
<Message>Error converting data type nvarchar to bigint.</Message>
<Source>.Net SqlClient Data Provider</Source>
<TargetSite>
Void OnError(System.Data.SqlClient.SqlException, Boolean, System.Action`1[System.Action])
</TargetSite>
<StackTrace>

The Customer is using the custom report in his environment.

Resolution:

 If You are using the custom reports in the system then at the time of Upgrade Installer doesn't make any changes on those reports as they are marked as a customized flag true.
There are certain mappings required to make that report compatible with iVend 6.6 as You are aware that there are schema changes have been done from version 6.5 Update 6 to the version iVend 6.6.
You need to make the changes on your own to make these reports compatible, however, if any assistance from the CXS Report Dev team is required then it would be a billable exercise.
Please check if the Report is a .RPT or .IRT report. To check the same go to the Report Manager in HO MC >>search the Transaction Receipt Report>>Export it into a folder and from them, you can get if it is a .RPT or .IRT report.
And as best practice, before the upgrade, there is a need to check how many reports are customized and if they are customized, then there is a need to make them compatible with iVend 6.6. It is because iVend 6.6 has schema level changes and Older Version reports may or may not work in iVend 6.6.
We have mentioned such practice points in the iVend 6.6 Pre-Upgrade Checklist and Post-Upgrade Checklist which may help partners to upgrade the iVend.
iVend 6.6 Pre-Upgrade Check list and Post-Upgrade Checklists are available in Document store<<Product documentation<<iVend Retail.