Re: Unexpected error: An item with the same key has already been added.

[Javier Treviño]

Hi Walter,
I am pretty sure the error you get is just because the "almost" duplicate tables.
I am pretty sure the problem is related to case sensitivity:
https://dev.mysql.com/doc/refman/5.7/en/identifier-case-sensitivity.html

This sound like a bug in MySQL for Excel.

If you can reproduce this only with a MySQL database where database object names are identical except for the casing, but not with other databases, please raise a bug report in https://bugs.mysql.com.

Include all information possible to recreate the problem.
Also include the value of lower_case_table_names used in the database you are connecting to; and any other information as of how you can use the same table names but with different casing will help.

Best regards.

====================================
Javier Treviño
MySQL on Windows Team