org.openqa.selenium.WebDriverException: [Exception... "Component is not available" nsresult: "0x80040111 (NS_ERROR_NOT_AVAILABLE)"

@Test
public void Workflowstatus() throws Exception {

        guitils.loginToPortal(userName1, password1, driver);
        guitils.LightiningView(driver);
        driver.findElement(By.linkText("ICIX")).click();
        Thread.sleep(3000);
        // TP Group 1
        TPO.create_tpGroup(driver, Group);
        Thread.sleep(8000);
        driver.findElement(By.linkText(Group)).click();
        Thread.sleep(8000);
        // set requirements 1
        driver.findElement(By.linkText("Set Requirements")).click();
        Thread.sleep(3000);
        driver.switchTo().frame(driver.findElement(By.id("vfFrameId")));
        Thread.sleep(3000);
}

I m getting mention error while its cliking on the "group" link as mentioned in code. Sometimes code working perfectly and sometimes it not

somebody please do the needful. Thanks a ton