Are you using ENVI or ENVI Classic. Which version?
While I'm not familiar with that particular error message, we do have a tool that you can run from the ENVI Toolbox (on the right side of the application).

1. Type "Run Task" in the search window of the toolbox.
2. Double-click the "Run Task" tool.
3. In the Run Task dialog, type "root" in the search window at the top.
4. Double-click the "Root Stretch Raster" tool.
5. Fill out the Root Stretch Raster dialog with your input image, minimum (0), maximum (255), and root index value. 2 is default.
6. Select an Output Raster filename and click OK.

You should get the result you expect. It will take some time since you have a large image. To answer your question, ENVI should definitely produce the histogram it needs for large images like this.