DM_GWPipeline_Gateway_MashupDataAccessError

[hello_]

Hello Experts, could you please help me with this error, 
I am trying to do refresh on my published report but having this error not sure what and why this is happening 
I have multiple MySql and MariaDB connection for Data Source
when publishing PBI asked me to configure on-premises Datagatway for every Data Source which I did for all and then tried to refresh the Semantic model and had this error 

Data source error: {"error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","pbi.error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","parameters":{},"details":[{"code":"DM_ErrorDetailNameCode_UnderlyingErrorCode","detail":{"type":1,"value":"-2147467259"}},{"code":"DM_ErrorDetailNameCode_UnderlyingErrorMessage","detail":{"type":1,"value":"The given credential contains a property with a null value. Data source kind: Web. Property name: Username. "}},{"code":"DM_ErrorDetailNameCode_UnderlyingHResult","detail":{"type":1,"value":"-2147467259"}}],"exceptionCulprit":1}}} Table: FC.


Thank you for you time and efforts 

[mark_endicott · Accepted solution]

@hello_ - your table named "FC" appears to be from a Web data source, and you've not entered credentials for it. 

If this is an open website that does not need a login, you will still need to enter an "Annonymous" authentication method on the data source credentials. See screenshot below:

If this works, please accept as the solution. 

[hello_]

Thank You @mark_endicott it Worked for FC as it was a google Sheet, 

Now I am facing this error in a table that is an append query of multiple MySql and Maria db connections i am having this Error now and I can't make the Authentication method to Anonymous as it is not giving the option only gives Basic and Windows.

Could you please help me with this 
Thank You so much for the above help as well 

This is the error 
Data source error: {"error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","pbi.error":{"code":"DM_GWPipeline_Gateway_MashupDataAccessError","parameters":{},"details":[{"code":"DM_ErrorDetailNameCode_UnderlyingErrorCode","detail":{"type":1,"value":"-2147467259"}},{"code":"DM_ErrorDetailNameCode_UnderlyingErrorMessage","detail":{"type":1,"value":"The given credential contains a property with a null value. Data source kind: MySql. Property name: Username. "}},{"code":"DM_ErrorDetailNameCode_UnderlyingHResult","detail":{"type":1,"value":"-2147467259"}}],"exceptionCulprit":1}}} Table: Client.

[mark_endicott]

@hello_ - You are now missing credentials on a table called Username which is a MySql table. 

I would suggest checking the credentials on the Gateway.

[hello_]

@mark_endicott 
I don't have any table named as username, 
and one more thing when mapping gateways - it also asks me to map some cloud connections as well I am confused  as why is it asking me that because I don't have any cloud connection in my PBI repost, Could this error be because of this 

[mark_endicott]

@hello_ - Sorry, I misread the error message, it's a Table called Client that now appears to be missing credentials. 

If you are being asked to map cloud connections, it indicates that your On-Prem gateway is missing some of your sources. If the data source was found on the Gateway it would map, and it seems the source for the "Client" table is not present. 

It could be that the connection strings are not identical so I would check everything you have created on the Gateway. 

I would also suggest you raise a support ticket with Microsoft. They have engineers especially designed to assist with these issues. You won't find them on a DAX forum.

You can do that here: https://admin.powerplatform.microsoft.com/newsupportticket/powerbi