"Duplicate output alias" error when appending

[ECowell]

Hi all,

I'm fairly well versed with Power Bi and Power Query, however i am absolutely baffled by this error

I am appending two tables to create a master employee file,
- one a hard coded dataset that doesnt change (employees that have already left)
- Two the EXACT same dataset but one that updates as and when an employee leaves / joins
Table 2 updates daily with the changes, so the aim is to use power query to append table 2 into table 1, remove duplicates and essentially keep a self-updating master file of all employees past and present

But when i appent the two through Power Query i get this error 

Neither table has more than one column with the same name, Both tables have the same columns with the same column headers
Table1 comes from an access database
Table2 is "get data" to a CSV File

Everything is formatted the same (Text)

If i change the column names of table 1, It just appends the two tables side by side

Does anyone have any advice on the best way for me to create this data?

Short version:

I have two tables containing employees, one access databse file, one CSV. 

the CSV file only contains current employees - If someone leaves, they drop off the file
The access DB contains all employees that have left as of today

I am currently manually updating the Access file to include all employees (pasting CVS below and removing duplicates)
I want to automate this process but for reasons mentioned above the power query append does not want to work

Does anyone have any suggestions on the best way to create this query / table, or how to fix my current issue?

Thanks in advance!!

[ECowell · Accepted solution]

UPDATE:

The issue was the name of the columns - despite Table 1 being a hard coded version of table 2, i copied and pasted the column headers from Table 2 into table 1 and it worked as it should...

I cant say i understand what happened and why, but it is resolved now - hopefully this helps someone else 

[lbendlin]

Go to your access db and remove the alias from the code.

Importing Queries to Blank DB created "Duplicate Output Alias" Errors | MrExcel Message Board

[ECowell]

Hey, thanks for the reply!

I'm not too sure what you mean though - the "duplciate alias" is the name of the column header in the export

When i change it to something different my table appends like the screenshot below

with the left most columns being the table from access db and the "null" columns being the CSV - if i filter out the nulls i get the same table in reverse

this has absolutely thrown me- the BI report has several other appended tables no problems but for some reason this one just wont work