The tool Compute Confusion Matrix does not start. ArcGis pro 2.6 (ERROR 999999: Something unexpected caused the tool to fail)

[ВалерияГабова]

I want to check the classification accuracy with the confusion matrix, but the tool is not working. I've done this previously in early versions of ArcGIS and it worked. What could be the reason?

ERROR 999999: Something unexpected caused the tool to fail. Contact Esri Technical Support (http://esriurl.com/support) to Report a Bug, and refer to the error help for potential solutions or workarounds.
Failed to execute (ComputeConfusionMatrix).

Failed to execute (ComputeConfusionMatrix).

[Robert_LeClair]

One thing I do when I see strange things like this is rename the ESRI folder to ESRI_OLD.  These folders are located in your C:\Users\<user_profile>\appdata\local and C:\Users\<user_profile>\appdata\roaming paths.  If it's worked in the past, I wonder if there's something "odd" here.  

[ВалерияГабова]

Thanks for the answer! Unfortunately this doesn't work for me. Hope someone can use your advice!

[Mary_Murphy]

Hi! What are you using as the Output Confusion Matrix name?

[ВалерияГабова]

Hi! Сonfusion_matrix, matrix, accuracy, or something like that.

[Mary_Murphy]

Are you saving it to a folder or a .gdb? If saving it to a folder, put  .dbf after the name, and keep the name short, sweet, no special characters, no spaces [the usual].

[GretchenRichter]

I had the same problem and this fixed it, thank you!

[JillC]

I'm having this same problem. Have you resolved the issue since posting? 

Mine worked for me until I edited some of the accuracy points but I don't see why that would make a difference.