Error Message: The specified key is not the valid size for this algorithm

[gooranga1]

Hi,

I have a xlsx spreasheet that I have inherited that connects to files on sharepoint. Initially this worked ok for me I can get access to the folders.

But now I am getting an error message when attempting to connect to the folders

Error Message:
The specified key is not a valid size for this algorithm.
Parameter name: key Key length: 40

Even if I try to attempt to create a new connection I get the same error in Excel. If I make the connection in Power BI Desktop it works fine. But it will not work in Excel.

I have deleted the cache folders to no avail and no I am stuck!

AppData\Local\Microsoft\Power BI Desktop\Cache

AppData\Local\Microsoft\Power BI Desktop\CEF\cache\Cache

Not sure what is messing up the Excel connection has anyone else had this issue with Excel?

[v-gizhi-msft]

Hi,

You should also delete one cache folder under Microsoft folder but not only under Power BI Desktop folder.

Best Regards,

Giotto

[gooranga1]

Hi @v-gizhi-msft 

I had seen a post that said this but I don't have a cache folder in the Microsoft folder to delete?

No Cache folder to delete

[gooranga1]

There is another folder that needs deleting. It's now fixed.

C:\Users\<username>\AppData\Local\Microsoft\Office\16.0\PowerQuery\Cache

This was posted by @jazz  in this post https://community.powerbi.com/t5/Desktop/Unexpected-error-The-specified-key-is-not-a-valid-size-for-... 

[Greg_Deckler]

Somebody posted about this recently, I think they had to change the api version or something associated with their sharepoint connection. Try searching for that error in the forums. You could check the Issues forum here:

https://community.powerbi.com/t5/Issues/idb-p/Issues

And if it is not there, then you could post it.

If you have Pro account you could try to open a support ticket. If you have a Pro account it is free. Go to https://support.powerbi.com. Scroll down and click "CREATE SUPPORT TICKET".