To add to problems faced installing, these are some of the things I had to do to install it on a multishop environment.
- If you can't install or uninstall, try reset. If you get it to install, copy the ps_product_comment* tables structure in case you need to repopulate it in the DB. When running into problems I found deleting the tables allowed it to reset. At other times, I had to reinstall the ps_product_comment* tables to install. I tried to uninstall without the tables, and it said 'module not installed' even though it was.. I put the tables back in and it uninstalled. If you are going to reinstall, make sure those tables don't exist.
- Make sure your products assigned to categories. I run a multishop environment and was having a lot of trouble. Once I made sure every product belonged to its proper category and shop, it installed on all of my shops without error. You can check this at Sell->Catalog->Monitoring to see if you have errant products.
- Also, I disabled modsec during install and it thats also when it worked. I re-enabled modsec and it is still functional. I don't know if disabling modsec is required, but it doesn't hurt to try if you're running out of things to try to get the mod installed.