How to add attribute table to a raster resulting from "weighted sum"

Question

I applied "weighted sum" tool to overlay three rasters, the resulting raster, however, does not have an attribute table with values and counts of each type of pixel.
When I right-clicked the raster, the "open attribute table" option is gray, but the values are calculated after using weighted sum.

How can I add the values to the attribute table?
I tried with Build Raster Attribute Table, but there always was an error saying the raster should be one band. In fact, the raster is one band. 
I am quite confused. Anybody can help?
Thank you

MajaTurkalj · Answer

This is an old post, but I will still reply. Hopefully, it can help someone. The Error 999999 is a generic error for which the cause does not have a specific error ID. In most of the cases when I had this error, I would just restart ArcMap. However, you can find the response from ESRI technical support regarding the error here: Error 999999.

Regards,

Maja

oraibalmegdadi · Answer

hi ..

i tried to use the int tool , but it gives me errors:

PrasantaBhattarai · Answer

I applied "weighted sum" tool to overlay three rasters, the resulting raster, however, does not have an attribute table with values and counts of each type of pixel.
When I right-clicked the raster, the "open attribute table" option is gray, but the values are calculated after using weighted sum.

How can I add the values to the attribute table?
I tried with Build Raster Attribute Table, but there always was an error saying the raster should be one band. In fact, the raster is one band. 
I am quite confused. Anybody can help?
Thank you

Greetings,
The output from the weighted sum tool is always a floating point raster. For you to be able to build attribute raster attribute table, the input raster should be a single band "Integer" raster. You can convert your weighted sum raster to an integer raster by running INTtool.
Regards,
Prasanta.