Gateway timeout error while importing the LMS.
NOTE: Some knowledge on why you are getting this error.
When you are loading huge amount of data to process web server needs more time to process, so by the time proxy/apache server does not receive the response it will respond with timeout error.
Few customers have huge set of data so obviously it is expected to get the timed out exception. This is the reason when you tried to import the same labels on different environment where you have less existing labels it worked without any issues.
Labels import logic checks for the every label is already available or not and depending on that it will do necessary updates/inserts into the table.
SAP SuccessFactors Learning - All Supported Versions
Akamai servers are configured to throw the timeout error at 2 minutes. If any request takes more than 2 minutes then you will be seeing this issue. As of now If customers are able to load the labels in the batch the label import is successful. We suggest the customer not to perform any action which exceeds the two-minute time limit.
When you import huge data or If any request takes more than 2 minutes then we will be seeing this issue.
Instead of importing all the labels at a time, try to import them in batches of 5000 labels. Anyway this is a one time process so customer won't face any issue doing in this way.
Gateway timeout , label import , KBA , LOD-SF-LMS-PER , Application Latency/ Performance Issues , Problem