NAV2015 Data Upgrade "Object ID Not Found" during processing

Hi all,

I've got a database that I'm upgrading from NAV2009 to NAV2016. So far, I have
1. Upgraded from NAV2009 to NAV2013, running the "Step 1" upgrade process that stores data in the temp upgrade tables.
2. Opened the database in NAV2015

The database has 4 companies.

Now I'm running the "Data Upgrade" process. It reports an error "Object ID Not found" in only one of the steps, for "Company 1" (out of 4). The other companies all process OK. Here's the detailed output from Get-NAVDataUpgrade. The error message is in the second block (Session ID 4969, Codeunit 104055):

SessionId    : 22
CodeunitId   : 104051
FunctionName : CheckPreconditions
CompanyName  : <Company 1>
StartTime    : 3/29/2016 5:00:49 PM
Duration     : 00:00:00.1406200
State        : Completed
Error        :

SessionId    : 4969
CodeunitId   : 104055
FunctionName : StartUpgrade
CompanyName  : <Company 1>
StartTime    : 3/30/2016 12:33:34 PM
Duration     :
State        : FailedPendingResume
Error        : Object ID not found.

SessionId    : 24
CodeunitId   : 104051
FunctionName : CheckPreconditions
CompanyName  : <Company 2>
StartTime    : 3/29/2016 5:00:49 PM
Duration     : 00:00:00.1562444
State        : Completed
Error        :

SessionId    : 29
CodeunitId   : 104055
FunctionName : StartUpgrade
CompanyName  : <Company 2>
StartTime    : 3/29/2016 5:00:49 PM
Duration     : 00:00:16.5935582
State        : Completed
Error        :

SessionId    : 25
CodeunitId   : 104051
FunctionName : CheckPreconditions
CompanyName  : <Company 3>
StartTime    : 3/29/2016 5:00:49 PM
Duration     : 00:00:00.1406200
State        : Completed
Error        :

SessionId    : 27
CodeunitId   : 104055
FunctionName : StartUpgrade
CompanyName  : <Company 3>
StartTime    : 3/29/2016 5:00:49 PM
Duration     : 00:15:32.3687797
State        : Completed
Error        :

SessionId    : 23
CodeunitId   : 104051
FunctionName : CheckPreconditions
CompanyName  : <Company 4>
StartTime    : 3/29/2016 5:00:49 PM
Duration     : 00:00:00.1406200
State        : Completed
Error        :

SessionId    : 28
CodeunitId   : 104055
FunctionName : StartUpgrade
CompanyName  : <Company 4>
StartTime    : 3/29/2016 5:00:49 PM
Duration     : 00:00:44.2494866
State        : Completed
Error        :

It appears that Codeunit 104055 (UPG6080.StartUpgrade) ran through all its steps, because the last thing that it does is run the following:

IF IsLastCompanyInDatabase THEN
  MarkUpgradeToolkit.MarkTablesForDeletion;

This changes the version tag of all the upgrade objects and other objects to be deleted - and it has done that.

Any ideas from anyone?

Thanks

Ron