Themida/WinLicense search for printable chars to be able to determine if a pointer to "something" is a string or not. As your string might contain special Portuguese characters the internal function to determine if a specific char is printable might fail.
You can change the current locale, so Themida/WinLicense will be able to find your Portuguese string.
1) Edit your Themida.ini/WinLicense.ini file and add under the [General] section add the following entry:
StrEncryptLocale = Portuguese
2) Restart Themida/WinLicense and go to the "Protection Macros" panel and click on your STR_ENCRYPT macro and make sure that your Portuguese strings can now be recognized
You can change the "StrEncryptLocale" entry for a different language, like "Russian", "Spanish", etc.