Hi,
I would suggest this sequence:
-- Check if required version of the browser is supported by the current version of TestComplete;
-- If the browser is not already supported, then use Version History (https://support.smartbear.com/testcomplete/docs/general-info/version-history/index.html) to find out at what version of TestComplte support was stopped;
-- Get proper version of TestComplete from your Customer Portal (my.smartbear.com), install it on a separate box and use it for testing for this browser. (Note: You might need to create a new test project for older version of TestComplete and populate it with components (script units, execution plan, etc.) from your current test project).
