While selecting the variant code in production order line my navision i.e. Navsion 2013r2 gets closed auotmatically.
Then i have to compile the table 5406 (Prod. Order Line). Then it allow to select me the variant.
It depends if you are a customer or partner.
Overview of Released Application Hotfixes for Microsoft Dynamics NAV 2013 R2
Overview of Released Platform Hotfixes for Microsoft Dynamics NAV 2013 R2
Even if you find that specific error on the list, then I would still recommend you to install the latest cumulative update of NAV 2013 R2, if you are much more than a few releases behind.
You can download the latest CU from October 2017 here: