When will V13.1.1 support end?
Solution
Since 13.1.1 is what is called a "Technology Release" version, support ends one year from the Release-to-Market date. Also, once the follow-on release version is available (in this case it was 13.1.2), all development and hotfixes for 13.1.1 cease. For 13.1.1, End of Maintenance was March 2018.
As a general rule, unless a company requires the specific functionality that has been added to a "Technology Release" version, the recommendation is to stay with the mainline versions (13.1, 14.0, 14.1, 15.1, etc...). You will have more consistent support (2-3 years from RTM, not 1), and a steady stream of hotfixes for any bugs found.
You will have GTAC support on a version as long as you have valid maintenance. If a fix for some bug is available in a later version, and the version you are using is past the end of maintenance date, your choice is either to upgrade, or continue to work in the version with the bug, as a hotfix will not be "rolled-back" into that version.
Notes and References
Hardware/Software Configuration
Platform: INTL64
OS: windows
OS Version: 1064
Product: TECNOMATIX
Application: PROCESS_SIMULAT
Version: V13.1.1
Function: LICENSING
Ref: 001-9662153