The forum search seems to work OK for me now.
For the crash, please try the suggestions in Crash, exit or high CPU usage when viewing certain directories, or the sister guide linked from there which covers crashes when right-clicking, if right-clicking is the trigger.
If there are crash dumps, you can also email them to me at leo@gpsoft.com.au but there is only a limited amount I can do with such an old version of Opus; I may be able to tell you if the crash is happening because of code in Opus itself or (more likely) because of code in a 3rd party shell extension, which is often enough to know which compnent needs updating or blocking from within Opus to avoid the crash.
it's also worth keeping in mind that Opus 10 is not supported on Windows 10, as the last Opus 10 update was released a long time before Windows 10 even existed.