Unable to Edit Excel Chart Template

Hi people.

I'm a fairly new engineering intern at a company and we use a lot of excel macros and chart templates to make charts from the data that we collect. We use one macro that calls a chart template to complete the job. A previous intern created the chart templates that we use today.

Here's my issue: I want to make a small modification to the chart template that we've been using (literally all I want to do is to increase the size of a text box in the chart). The template is of course a crtx. file which I cannot open. How can I edit crtx. files? I am able to open up the template (mind it only the chart shows up with no data) when going to Excel -> Insert -> Insert Chart -> Manage Template -> Then I chose the template. I tried to edit that chart and then save that as a new template/overwriting it but that doesn't work. Do I need to find the original files that the previous intern used to create this template? I've tried that but no luck so far.

Please let me know if I'm not explaining my problem clearly. Any help is greatly appreicated!!

Thanks!

Thanks for your reply.

It could be that. Whenever I do save it as a new template and open it, nothing shows up. When I look at the file size, it says 0 KB. I did find a way to get around my inital issue but it would be nice to find out what for sure went wrong here..