I've successfully created a new menu link to a multisites shared article, however when I try to click on the link in the front end I get the following error:

Fatal error: Class 'ContentHelperRouteOrig' not found in /home/domains/MYDOMAINNAME/components/com_multisitescontent/helpers/route.php on line 48

Which is your joomla version ?
and JMS version ?
and article sharing version ?

Everything is a fresh new install.

Joomla 2.5.4
Article Sharing 1.1.5
Multisites 1.2.87

Anything? Any help here?

Did you installed the JMS patches ?

Which menu item type did you select ? feature, specific article, blog, list, ....

Can you describe the parameters and give screenshot of the configuration that you are using.

We are not able to reproduce this problem.
We have installed a Joomla 2.5.4
- Installed JMS 1.2.87
- Installed the JMS patches
- Installed the Article Sharing for JMS

Created a specific "shared category" for the test
We create a "shared article" that we put in the "shared category".

After that we created a menu item where we selected the "Multi Sites article layout" and selected the article.

The article is successfully displayed.

All the JMS patches are installed. I have tried ALL of the Article Sharing types: feature, specific article, blog, etc. They all produce the same error.

I'm not sure what you mean by create a "shared category". There is nothing in the instructions that I saw about needing to create specific shared categories... Aren't all of the categories and articles "share-able"? There is nothing in the user manual on this topic that I could find.

What specific part of my configuration are you looking for a screenshot of? My server Control Panel? Joomla Administration home page? Whatever you need I will provide.