Trouble to modify a reference style -

I try to modify APA 6th but having a trouble to save the modified style. 

I am using EndNote X7 (7.5) with microsoft WORD. 

My modification is really simple that just want to change numbers of list of authors in citation.

To do that, I followed: Edit > Output Styles > Edit "APA 6th"

Then, changed number of listed authers through Author Lists in the side manu. 

Then, click x.

In the popup window that asked me "Save changes to the EndNote sytle file “APA 6th” before closing?", 

I clicked " YES".

The following pupup window “Save As” , I clicked “Save”.

However,  the “Save As” Popup window comes again and again but not actually saved the modifiied referece

Does anyone can help on this issue?

 

Thanks for the comment. As you said, the style folder was in C drive and I moved this to my doucment folder. Then, all is good now. Thanks.