Export/Import Tool JNeuhoff - Import problem

I get an error when trying to import previously exported xlsx product list:
Uploaded spreadsheet file has validation errors!
See also 'System > Error Logs' for more details.
No server data has been changed.

in the system log is:
2016-03-08 22:39:52 - Export/Import: Worksheet 'Rewards' cannot use product_id '181' because it is not listed in worksheet 'Products'!

In the exported list of products there was no product with 181 ID. Product with this ID was removed from my store a long time ago.

Please let me know the solution because I need to update my product database with new products.

As it says: "Worksheet 'Rewards' cannot use product_id '181' "

Remove that line from the rewards worksheet.

No, it's not a solution because this product_id is in the exported file and deleting it does not help.

After upgrading to 2,31 version I exported products and tried to import the exported file again and i get the following error:

Uploaded file is not a valid spreadsheet file or its values are not in the expected formats!
See also 'System > Error Logs' for more details.
No server data has been changed.

2016-03-13 22:40:31 - error_unlisted_product_id

I didn't change the exported file.

Your database is corrupted, and your upgrade to 2.31 wasn't complete, either. The error_unlisted_product_id isn't possible because this text string is clearly listed in the admin/language/english/tool/export_import.php. I suggest you do a proper re-install of the Export/Import tool!

As regards the database: Remove all entries from of oc_product_reward where product_id = '181', using PHPMyAdmin.

I use polish language,
Ok,
I solved the problem witj 181 ID.

I have exported the product's using "Products (including product data, options, specials, discounts, rewards and attributes)" option.

After export i did import usingexported file and I get an error:

Uploaded spreadsheet file has validation errors!
See also 'System > Error Logs' for more details.
No server data has been changed.

System logs:
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!
2016-03-16 12:40:25 - Export/Import: Undefined attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' used in worksheet 'ProductAttributes'!

I've checked the attributes. everything seems to be ok. attribute_name 'Rozmiar' for attribute_group_name 'Haczyki' is correct and defined for such product group.

Please check your Attribute definitions for attribute group 'Haczyki' and attribute 'Rozmiar'. In particular make sure there are no leading nor trailing white spaces used in their names!

There was a trailing white space at attribute 'Rozmiar'. I've done the test export na import and everything seems to be ok. Import was a success.

Thank You for Your help.