@Waheed1 and @townerusa
I had the same problem with installing new plugins, every time i try to install a new plugin through wordpress dashboard, it keeps showing a 500 error.
What i did and what i suggest you to do is to try installing the plugins through cPanel. (My site is hosted by godaddy and i use cPanel directly from GoDaddy to install the plugins) This has fixed my problems, and hope to fix yours too.
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