rolling back to previous version

Dear Community please help

I am having serious issues using KNIME since i upgraded it to the newer version. I have rebooted my machine at least 3/4 times. I cannot use my old work. Today it has taken me 3-4 hours just to figure out how to rename columns, and I still have not been able to do so. I cannot open the configuration dialogue box when I double-click on the Column Renamer node. I tried using the Column Rename (Dictionary) node but had no luck there as well. I cannot double-click on many column-related nodes, and it looks like I am missing an extension. For example, I cannot double-click on the Column Filter node either.

Please help. this is too depressing and frustrating