Error: unresolved reference to function 'get.object.tiv'
How to solve?

That's hard to tell based on the little amount of information we have. I'm guessing it's some version mismatch. The report has been imported from a newer system onto an older one. So the report uses functions the environment does not know.
My Programmers Guide of LN 10.3 does not know the function "get.object.tiv", so it may have been introduced somewhat later (or is undocumented).

Change the Tools interface version of the report to the latest one...You can find the standard report and check its TIV and put the same for your report and then please check..