As we know you can not open Nintex Workflow Designer for an UDA at Farm level in all versions of the product. So that begs the question how do we update an UDA at Farm Level if we need to change it? This is a question a Partner had and they shared their workaround with us. So I am sharing it with the community as I see it as being very useful.

The official method is using two farms. Editing the UDA in Farm A at site level then publishing at Farm Level in Farm B. This is not particularly convenient for single farm deployments. The reason behind this is that for an UDA to exist in a farm it needs a unique ID. Creating UDA's at site level to import over the farm level ones does not work since they have different ID's. 

Details on how UDA's are identified.

The UDA has a unique ID and Static GUID 

     - These can be referenced in the Nintex Config DB under the UserDefinedActions table. 

The workaround 

In Nintex Workflow 2010, 2013 and 2016, you can circumvent this limitation by editing an UDA at site level and this is achieved via modifying the UDA ID in your browser (IE 9+) URL. The result will redirect the designer session to target the Farm/Server UDA. 

By changing those values you can modify the farm level UDA. 

Known issues

If the central administration web application is on a different authentication model than the location where you opened the UDA, then the designer will not load as expected. 

This method is not an offical method. Should issues come from using this method it will not be supported by Nintex Support Team

Help file 2010 / Help file 2013 / Help file 2016     Please note these references will be updated soon.