Most environments are available through the Tekla Downloads portal.
Local environment settings - env_.ini - Trimble User Assistance - Tekla tekla environment list
A: Immediately close the model without saving. Re-open Tekla, pick the correct environment, and start a fresh model. Do not try to "fix" it later. Most environments are available through the Tekla Downloads
Example output might look like:
: A standard "blank" environment containing generic settings and templates that serve as a baseline. Blank Project pick the correct environment
: Settings like env_US.ini that define how Tekla starts and which folders it searches for data.