[KevinH]

I will check the code that converts from named entities to numeric entities to see why this is happening.

Update:

The ePub3-tizer code explicitly protects against converting anything in pre tags.

I have found two different sources that say only xml entities are allowed inside pre tags and no others. It could be that other named entries are not supported since what is entered in the tag is supposed to be pre-formatted aside from xml entities.

And afaict there is no valid reason to use nbsp in pre since you control the line breaks. So I am not sure the original xhtml code was valid to begin with. I will see if I can find a clearer spec.

Update: now found one reference that implies they are legal.

Are you using Sigil's Preserve Entities preferences and is it set to allow only the numeric value of nbsp before you run this plugin? If not, please try that.