Excel2013 to Excel2016 problems with save old files

[borigi]

Hi,
In my company decided to upgrade excel from 2013 to 2016. Everything fine but now I have a big issue on reopening and saving old files.
Actually it does open just when I want to save it (or save as...) I get multiple errors.
When I open the "repaired file " I get this:

Excel was able to open the file by repairing or removing the unreadable content

Repaired Records: Formula from /xl/worksheets/sheet2.bin part
Repaired Records: Formula from /xl/worksheets/sheet3.bin part
Repaired Records: Formula from /xl/worksheets/sheet4.bin part
Repaired Records: Formula from /xl/worksheets/sheet5.bin part
Repaired Records: Formula from /xl/worksheets/sheet7.bin part
Repaired Records: Formula from /xl/worksheets/sheet8.bin part
Repaired Records: Formula from /xl/worksheets/sheet9.bin part
Repaired Records: Formula from /xl/worksheets/sheet11.bin part
Repaired Records: Formula from /xl/worksheets/sheet14.bin part


where the formulas on mentioned sheets couldn't be easier.
On sheet2 there is only one formula and it say:
=CONCATENATE(" ";Nastavitve!I4;TEXT(GETPIVOTDATA("Min of Datum";Datumi!$A$3);" dd.mm.yyyy");" - ";TEXT(GETPIVOTDATA("Max of Datum";Datumi!$A$3);"dd.mm.yyyy"))

and there is a pivot table and one slicer and no other formula...

Is this related to new excel or what could it be?
It just came to the point I have no clue how to continue.
Please help

 

[borigi]

whenever I try to save file with pivot tables in excel2016 which were created in excel2013 it prompts:
"Errors were detected while saving"... "to make repairs in new file..."
After I click [continue] it says: "Excel encountered errors during save. ..." and saves an unusable file to an excel folder
with final message: "Damage to the file was so extensive that repairs were not possible. Excel attempted to save your formulas and values, but some data may have been lost or corrupted."

It is most interesting that it does open without any comment and I can also insert data and work in it like everything is normal.
just it is impossible to save the file afterwords.

Anyone have any idea what this could be?

 

[borigi]

solved it.
there was an error in pivot table...