When exporting from Selenium IDE to Webdriver, some commands are not getting exported. Its coming as "Unknown Command"

Question

driver.findElement(By.linkText("Add User")).click();
// ERROR: Caught exception [unknown command [readCSV]]
// ERROR: Caught exception [unknown command [while]]
// ERROR: Caught exception [unknown command [storeCellValue]]
System.out.println("${AddUser}");
driver.findElement(By.id("userid")).clear();
driver.findElement(By.id("userid")).sendKeys("${AddUser}");
// ERROR: Caught exception [unknown command [storeCellValue]]
System.out.println("${AddUserType}");
new Select(driver.findElement(By.id("userType"))).selectByVisibleText("${AddUser}");
// ERROR: Caught exception [ERROR: Unsupported command [isTextPresent | PG Admin | ]]
// ERROR: Caught exception [unknown command [storeCellValue]]
System.out.println("${Firstname}");
driver.findElement(By.id("firstName")).clear();
driver.findElement(By.id("firstName")).sendKeys("${AddUser}");
// ERROR: Caught exception [unknown command [storeCellValue]]
System.out.println("${MiddleName}");
driver.findElement(By.id("middleName")).clear();
driver.findElement(By.id("middleName")).sendKeys("${AddUser}");
// ERROR: Caught exception [unknown command [storeCellValue]]


new Select(driver.findElement(By.id("userRole"))).selectByVisibleText("${AddUser}");
// ERROR: Caught exception [ERROR: Unsupported command [getEval | ${i}+1 | ]]
// ERROR: Caught exception [ERROR: Unsupported command [addSelection | id=institutionAllowed | label=ALL]]
driver.findElement(By.id("btnAdd")).click();
driver.findElement(By.xpath("//input[@value='Add']")).click();
assertTrue(isElementPresent(By.xpath("html/body/div[5]/div/div[6]")));
// ERROR: Caught exception [ERROR: Unsupported command [captureEntirePageScreenshot | D:\Selenium\seleniumIDE\Screenshot\test${i}.png | ]]
driver.findElement(By.linkText("Click Here to add more")).click();
// ERROR: Caught exception [unknown command [endWhile]]**