a port number must be specified as the last field in the first line of the service.txt file. The recommended range is 27000 to 27009

Error Message

When attempting to import ArcGIS Pro Named User licenses into ArcGIS License Manager, the import process is halted, and the following error message is returned:

Error:   
Error: a port number must be specified as the last field in the first line of the service.txt file. The recommended range is 27000 to 27009. 

Cause

The ArcGIS License Manager service.txt file is incorrectly configured and contains a symbol in the port range section.

Solution or Workaround

To resolve the error, open the ArcGIS License Manager service.txt file, and edit the file to ensure there are no symbols in the port range.

1. Navigate to the following directory on the host machine, and open the service.txt file.

C:\Program Files\ArcGIS\LicenseManager\bin

2. Ensure the first two lines of the file follow the format below. Remove all unnecessary symbols or characters.

SERVER this_host ANY 27000
VENDOR ARCGIS PORT=<portvalue>

Note: 
Any value between 27000 and 27009 can be used for VENDOR ARCGIS PORT.

3. Save the new default service.txt file on the desktop.
4. Navigate to the directory in Step 1, and rename the service.txt file to service.txt_old.
5. Copy the new default service.txt saved in Step 3, and paste it in the directory provided in Step 1.