Hello Yen,
So... I've changed the file you mentioned, but in reverse. The error message no longer appears and the function to change the view is working perfectly. There still remains two problems that I identify as the following:
1. The parameters, are set in 8 articles to appear by default in the frontend, but only three appears, even clearing the cache from joomla etc.
2. When we click the "load more" button, instead bring other items from the category, the module replicates only those already are displayed in the frontend.
I believe that all module parameters are set correctly ....
Could you please check these questions?
Thanks for helping me! All the best!
André