This is a problem with the Spanish translation. Several format specifiers have been incorrectly included in two specific translation entries (‘%1$tráfico’ instead of ‘%1$stráfico’, ‘%1$traducciones’ instead of ‘%1$straducciones’, ‘aumentar%2$ tu’ instead of ‘aumentar%2$s tu’ …)
It should already have been corrected, but the incorrect translation files:
gtranslate-es_ES.l10n.php
gtranslate-es_ES.mo
gtranslate-es_ES.po
are still in /wp-content/languages/plugins
Simply delete them so that they are reloaded, and the problem will be solved.
