Unexpected error: The specified key is not a valid size for this algorithm.

[JamesGordon]

Hi all,

For some reason all of my PowerBI file come up with this error in  Power Query " Unexpected error: The specified key is not a valid size for this algorithm."

I have found other posts with the same issue - they mention deleting some cache folders.

Can someone shed any further light on this? Do i delete the entire folder or just the contents?

The only cache folder i can find is this one: C:\Users\<username>\AppData\Local\Microsoft\Office\16.0\PowerQuery\Cache

Are there other Cache folders i need to delete also?

Any help would be appreciated as this appears to be affecting all of my Powerbi reports!!

[JamesGordon · Accepted solution]

Hi @Pragati11 ,

I have deleted both:

C:\Users\James\AppData\Local\Microsoft\Office\16.0\PowerQuery\Cache

and

C:\Users\James\AppData\Local\Packages\Microsoft.MicrosoftPowerBIDesktop_8wekyb3d8bbwe\LocalCache\Local\Power BI Desktop

Deleted the files when Power BI was closed. Then re-opened but the error is still active?

Would it be of assistance if i posted the entire error?

[Pragati11]

Hi @JamesGordon ,

You can just delete everything inside Power BI folder on the following location:

C:\Users\<username>\AppData\Local\Local\Microsoft\Power BI Desktop\

Then re-start Power BI and try again.

If this helps and resolves the issue, appreciate a Kudos and mark it as a Solution! 🙂

Thanks,

Pragati

[JamesGordon]

Hi @Pragati11 

Thank you for a quick reply. I have tried to look for that folder but to no avail? Screenshot of my files below

Would there be anywhere else the folder could be?

[Pragati11]

Hi @JamesGordon ,

Are you on Windows10 machine? Also, try un-hidding any folders in this location.

I am using a Windows 10 machine and I have this folder.

If this helps and resolves the issue, appreciate a Kudos and mark it as a Solution! 🙂

Thanks,

Pragati

[JamesGordon]

Hi @Pragati11 

Im using Windows 10 also. I have hidden folders set to display but still no PowerBi Folder - screenshot below.

The only place i can find anything that relates to power bi was in this location: C:\Users\<username>\AppData\Local\Microsoft\Office\16.0\PowerQuery\Cache

I have tried deleting the files from that location but the error persists?

[Pragati11]

Hi @JamesGordon ,

The folder location that you are mentioning is for Microsoft Excel Power Query I think. That's why clearing cache there is not solving your issue.

Can you run a search on your C-drive for "Power BI Desktop" folder?

Because this folder definitely needs to exist somewhere on your machine.

If this helps and resolves the issue, appreciate a Kudos and mark it as a Solution! 🙂

Thanks,

Pragati

[JamesGordon]

Hi @Pragati11 

Thanks for your patience with this.

I have searched and the results as per screenshot below: I have circled the file i suspect might be the one we're after? its contents is in the second screenshot

If i then look into the App Data file the third screenshot show the contents

Is it any of these folders?

[Pragati11]

Hi @JamesGordon ,

Did you try deleting the contents shown in your 3rd screesnhot?

If this helps and resolves the issue, appreciate a Kudos and mark it as a Solution! 🙂

Thanks,

Pragati

[JamesGordon]

Hi @Pragati11 

i have deleted the contents but still the error as per below!!

Any other ideas?

I can copy and paste the whole error if that helps?

[Pragati11]

Hi @JamesGordon ,

Did you also delete the files on the following location:

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

Then close Power BI and open again and check.

If this helps and resolves the issue, appreciate a Kudos and mark it as a Solution! 🙂

Thanks,

Pragati

[JamesGordon · Accepted solution]

Hi @Pragati11 ,

I have deleted both:

C:\Users\James\AppData\Local\Microsoft\Office\16.0\PowerQuery\Cache

and

C:\Users\James\AppData\Local\Packages\Microsoft.MicrosoftPowerBIDesktop_8wekyb3d8bbwe\LocalCache\Local\Power BI Desktop

Deleted the files when Power BI was closed. Then re-opened but the error is still active?

Would it be of assistance if i posted the entire error?

[JamesGordon · Accepted solution]

Hi @Pragati11 

Thanks for you help. The error has now gone - i found some more Cache Files. For summary incase anyone else has this issue i deleted:

C:\Users\(username)\AppData\Local\Microsoft\Office\16.0\PowerQuery\Cache

and

C:\Users\(username)\AppData\Local\Packages\Microsoft.MicrosoftPowerBIDesktop_8wekyb3d8bbwe\LocalCache\Local\Power BI Desktop

And

C:\Users\(username)\Microsoft\Power BI Desktop Store App\ExtensionCache