Our organization has been struggling with the subject issue for 1-1/2 years. Mainstream Support has been discontinued outside of paid support. Microsoft did address the issue under an open ticket for resolve and they replicated the issue on their
end as a problem. A couple of non-working workarounds were provided, albeit unsuccessful. The issue is therefore a software bug from our standpoint.
Basically, we have several project files and we are fully integrated with linking to each others tasks. On average 5-10% of each project files tasks externally linked simply do not work and default to Project Start date for any particular project. I've tried every option for ensuring the syntax for linking is correctly established and it's correct, although not working still in several links.
While I don't understand how Microsoft couldn't find and fix the originating bug, I'm curious who else has had the same issue. We are considering upgrading to 2013 or maybe 2016, but honestly 2010 although an old version, should still perform the most
basic function of any scheduling software on the market. You don't see this issue in higher end programs like Deltek Open Plan or Primavera, regardless it's something Microsoft couldn't figure out.
Other 2010 users have also reported the same issue with no resolve and I remain confident someone figured out something, other than upgrading to a newer version. External linking has been around for a long time with Microsoft and 2010 apparently had
many bugs even after the two service patches, monthly software updates post mainstream support, etc.
Appreciate any other users with this issue chiming in.