Since Dynamics NAV version 2015 the server can send add-ins to the Role Tailored Client when they are needed on the client. This is a great feature, which helps add-in developers deploy the solution without much effort from the developer or the end user. However, this automatic deployment does not send updated DLL files to the client when they are updated on the server. Therefore, you may need to help it a little if you update your add-in DLL on the service tier. The service tier will send the updated DLL to the client if you clear the cache on the client.
Clearing the cache
You can reset the add-in cache by deleting the temporary files for the client. Each Windows user has a separate cache folder located under the folder for temporary files. This is where the service tier sends the add-in files when they are needed on the client.
Locate the cache by entering the following in the address line of the file explorer:
%TEMP%\Microsoft Dynamics NAV\Add-Ins
If you delete the files in this folder, the cache is cleared and will receive fresh DLL files from the service tier.