When accessing the below documentation help links in the customer's IT environment and UR environment for the languages GB and ZH, the results are as follows.

These fail: 
https://cml-erp06.cml.plc:48080/ifsdoc/documentation/gb/OnlineDocNav/rwc.htm?assemblyname=Ifs.Application.InfoServices&featurename=ReportArchive
https://cml-erp06.cml.plc:48080/ifsdoc/documentation/zh/OnlineDocNav/rwc.htm?assemblyname=Ifs.Application.InfoServices&featurename=ReportArchive

Whereas this works (which is included by default): 
https://cml-erp06.cml.plc:48080/ifsdoc/documentation/en/OnlineDocNav/rwc.htm?assemblyname=Ifs.Application.InfoServices&featurename=ReportArchive

We also need the documentation help links to work for the Chinese (ZH) language as well.
When explicitly login in from IFSAPP using the GB or ZH languages the issue still occurs. We have confirmed that the GB and ZH languages have been installed as we are able to login using the languages and the translated texts do appear in the application. But the links do not work. 
We managed to create a symbolic link for GB according to tech documentation, but there is a concern that since this will be using the EN content that there should be differences specific to GB which will not be displayed. Such as for example the word Color and Colour. And we cannot really use the symbolic link to work for ZH.

The customer is an on-prem customer using APPS10. Greatly appreciate it if any input can be provided. Preferably the checks we need to perform on our end to understand why this is not working by default even when the languages have been installed.