Hi,
It seems there is an issue with FontAwesome Pro and Joomla 3.8.
Can't access Extensions > Modules or Extensions > Plugins in admin with ISIS or ATHOR template, caused by JModuleHelper (see this thread https://github.com/joomla/joomla-cms/issues/18003).
Once FontawesomePro is deactivated it worked again; (simply renamed folder in system/plugin)
Thanks
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