Ok I figured it out after some experimentation. The Portuguese tags contain the "internal map action keywords" string list tag translated into Portuguese but left all the template tags in English. So when you open the Map Actions in Loathing, none of the parameters match the internal map action keywords. This was causing the crash. There are two ways to fix this.
One way is to alter all the template tags to use the Portuguese keywords instead of English keywords. This would be easy copy and pasting, but the rest of the templates (like descriptions and parameter names) would still be in English unless someone translated them. The second way to fix this is to just use the English keywords.
Since the second choice is a lot easier, I made an addon patch with just that tag. Download the
English Loathing Fix. Extract it and place the plugin in your plugins folder. Now when you load Loathing (1.7 or higher), you will not crash.
By the way, now that we have the tags, you can remove that link so others can't download it. Funny I had to download a 312 MB zip only to find out a 521 byte sized tag was causing the crash.