Resolve MapInfo Pro licence Activation Error: Unable to process trusted activation request transaction id 15,557,865. Please retry after a while.

Product affected: MapInfo Pro™

Issue

After transferring MapInfo license from previous machine to Flexnet successfully, trying to activate MapInfo on new machine produces the error " Unable to process trusted activation request transaction id 15,557,865. Please retry after a while." 

Cause

There are two reasons behind this error

1. There may be an incorrect serial number and access code in  Registry(i.e  HKEY_CURRENT_USER>Software(For 32-bit os)/ Wow6432Node(for 64 bit so)>MapInfo>MapInfo>Professional>ver. number).

2. MapInfo Pro is unable to connect to Flex net.

Resolution

UPDATED: December 6, 2019
1. Edit the Registry Entries (i.e  HKEY_CURRENT_USER>Software(For 32-bit os)/ Wow6432Node(for 64 bit so)>MapInfo>MapInfo>Professional>ver. number) with correct serial number and access code.

2. Try using the Email activation option to create a request.xml/response.xml as outlined in Activating a node-locked license.