The site uses WPML. The language is spanish (ES). I cannot change the language because I have to change it in WPML and I prefer not to change the settings of the plugin (it is an e-commerce operative site and I try not to change the configuration).
Talking with a programmer, he told me to change this line (the line with the error):
<p><b style’font-weight: 700;’>” . sprintf( __( ‘Exclusive offer!%s We don\’t run promotions very often, but for a limited time we\’re offering %s60%% off%s our Pro version to all users of our free Instagram Feed plugin.’, ‘instagram-feed’ ), ‘</b> ‘, ‘<b style=”font-weight: 700;”>’, ‘</b>’ ) . “</p>
to this line:
<p><b style’font-weight: 700;’>” . sprintf( __( ‘Exclusive offer!%1$s We don\’t run promotions very often, but for a limited time we\’re offering %2$s60%% off%3$s our Pro version to all users of our free Instagram Feed plugin.’, ‘instagram-feed’ ), ‘</b> ‘, ‘<b style=”font-weight: 700;”>’, ‘</b>’ ) . “</p>
and the error does not appear again. But I’m afraid that in the next update, the error appears again.
Thank you very much