Welcome the Technical Support section. Help us in assisting you by providing us with a concise and descriptive elaboration of your issues. Be specific and if possible, provide us with a step-by-step instruction in replicating your problem.
I have different error, I suggest you contact your sys-admin to inspect this issue further, if this issue related jomsocial please let us know and provide me the error detail.
You can review the error in the error_log file, a sample of the error is provided here:
[06-Oct-2016 11:28:46 America/Chicago] PHP Parse error: syntax error, unexpected '$result' (T_VARIABLE), expecting '(' in /home3/adcbb01/public_html/components/com_community/models/profile.php on line 251
As this is an issue with the code on the site, we would be unable to know why some pages load and others do not.
Regarding updates, this will typically not repair or replaced plugin or component files. Once repaired we can review your site for any issues with the update function. If you have any questions, let us know.