The software that Translation companies use for XLIFF can sometimes add segmentation information into XLIFF files. The issue occurs when the 'Do not store segmentation information in the translated file' option in the translation settings is NOT ticked
When this occurs your XLIFF file will include the following "mrk" tags 

Example XLIFF containing mrk:

Importing an XLIFF that contains mrk code can cause text assets to appear blank. 

Example gomo Editor after XLIFF import:

Resolution

There are two methods for resolving the issue

1. Contact your Translation Agency and request they provide the translated XLIFF without the mrk tags

2. Manually remove the mrk tags from the XLIFF

Steps to manually remove mrk tags

The mrk tags need to be removed from the XLIFF files in order for the import to work correctly. To do this you will need to download a free piece of software called Visual Studio Code

a) Download Visual Studio Code - https://code.visualstudio.com/ 

b) In Visual Studio click File > Open Folder and search for the XLIFF file on your machine

c) Click Edit > Replace in Files

d) Click the Use Regular Expression icon (highlighted on the right) and enter <mrk.*?>|</mrk> in the search field (highlighted on the left). This will show the amount of times the mrk tag appears in all the files in the XLIFF

e) Then click the Replace All icon. This will remove any mrk tags from the XLIFF files

f) You do not need to save the changes in Visual Studio Code. This is done automatically.
g) You can then upload the XLIFF files into your gomo course