Links breaking from two workbooks

For three years I've created a workbook (A) that is dependent on another workbook (B) I upkeep. When I open (A), I Edit Links and update the location to my newest weekly file to map from (B). For my 2014 (A) book, I did the same process, but when I update the values, all the links break. Only when I open up (B) with (A) will the values appear.

As a short term solution, I saved (A) with the values in there and disabled the prompt to update values, so others can see the data. This isn't a feasible long term solution since updates will be made weekly, and not everyone will want to open up (B) just to update (A).

Please advise, and thank you in advance!

I set the updates to automatic and the links broke. I had to default back to no updates and save the document. Could this be a security issue with excel 2010? I'm just confused as to why most my workbook links update just fine. Any other avenues to explore?

I created the main workbook in 2011. The linked workbook was created in 2009. When I click save as, both spreasheets show up as Excel Workbook. I don't see an option to ensure 2010 for both, but this could be the issue since my linking file was created pre-2010. Do you know how to ensure they are both 2010 version of excel files?

I opened both files and saved as, and created newer versions, then repeated the link update. The links then broke. Definitely not using mac for either. Both were created and have always lived in windows land.

Thanks for the brain storming. Let me know if you can think of other things to check. This is a weird one for me.