Restore Tas in Chrome

Need help restoring tabs in Chrome. browser session with multiple tabs was open and miinimized, and a new tab was opened. When the newly opened tab was closed, I couldn't find the minimized session. I opened other tabs to try to restore, but the 'Recently Closed' option i the History menu was at first bolded, but not clickable, now it is dim and not clickable. Chrome Version 49.0.2623.112 m. Widows Vista.