Mr Papa said
please see:  http://codex.simple-press.com/.....on-errors/

if not the issue, please look in error log for more info...

Thank you for your reply. I was forced to deactivate all plugins in order to regain access to the admin panel. From there I activated the plugins one by one, leaving simple:press for last. This reproduced the error. I then repeated the process, but I activated silver:press first, deleted the buddypress plugin, and then reactivated the remaining plugins and everything seemed to be working fine again. I then redownloaded and reinstalled the buddypress plugin and had the same result (i.e., the 500 error mentioned above). 

When you say to look in the error log for more infer, could you please be more specific? What do you suggest I do if/when I find an error? Post it here? Thanks again for your time. 

Mr Papa said
did you read the link I gave you???  if so, did you try it??  you did not say so...

look at the simple press budypress plugin and make sure its named buddypress and not buddpress-1 or some other number at end...  an issue with the internal wp uploader...

look in wp-content/sp-resources/forum-plugins

Yes, I did. I apologize for being vague. I just tried it again... same error.

Mr Papa said
tried what again???  nothing to try or redo...  just need to see if the directory is named properly or not?

I tried installing the plugin again. The directory is correctly named. 

Mr Papa said

installing it again is not the same.. if wp is adding digits it will do it every time...  so as long as its named right then okay...  but its one of the few things that would cause this...

other than that, you really just need to find your server error log (location varies by host) and see if more info... you could be running out of php memory...  or somethng else that can be worked...

As I said, the directory is correctly named (not just the .zip file, but also the directory stored on the server in the so-resources > forum-plugins). 

I think it probably has to do with php memory... here is one of the errors from the log:

Why would the buddypress plugin cause this? Maybe it doesn't play nice with another plugin?