Unable to add extension to Google Chrome after version 68

I have TestComplete 12.50 used by my company, few days ago I accidentally removed TestComplete Test Extension on Google Chrome v68.0.3440.75 (64 bit), as a result I can't run functional test for web application any more. I tried many method:

1. Go to C:\Program Files (x86)\Common Files\SmartBear\tcCrExtension and drag tcCrExtension.crx to chrome://extensions/ after swith to Developer mode, it pop up Add extension window but no extension being added after click add extension. 

2. Search on Chrome Web store for extension, no results

3. Delete TestComplete and reinstall again, No extension being automatically added to Google Chrome

4. Download tc_12_50_4142_Chrome68_patch and attach file to correct location following instructions. Still unable to run functional test for web applications. 

 

I am out of ideas, any ideas to solve this problem?

 

 

Thanks