There are numerous things that 'might' be the reason for your problem just as this suggests many possible approaches to fix the problem. Things such as making sure adequate or even added amounts of RAM have been allocated to LW. Rebuilding your desktop after installation (sometimes installing software can cause some light to heavy corruption to your desktop file & this will affect the overall running of your computer from a to z, causing much instability & slow responses, particular when you're in the Finder). To rebuild your desktop, restart your computer & hold down the Command + Option keys whilst it is restarting. Eventually it will ask you if you want to rebuild yor desktop. Press yes, & wait a few minutes (depending on the size of your HDD & no. of files) for it to complete. If you have more than one partition or HDD, rebuild those as well. It's a healthy thing to do on a fairly regular basis if you move a lot of files.

Make sure you have the most up-to-date version of Java for OS9. And yes there is an uninstaller. Problem is I can't remember where to find it. When you first open up the LW installer there should be an uninstaller included (a separate program file.) From memory, & I might be wrong here, LW installer acts as a disk image & it is somewhere within or somewhere else on your desktop that the uninstaller will be found. Try opening up the installer again & search around on your desktop.

Is this your 1st version of LW? Did you delete the previous version or install over the top?

(I'm just a little curious, why are you using OS 9.1 & not 9.2.2?)

If these suggestions don't work, get back to us. Also take the time to view other threads & posts on this forum. There may well be one with a similar issue.

And also make sure your computer is in good shape before you attempt to reinstall if that's what you end up doing. Run whatever disk & file utilities you have to check the condition of your hard disk drives, files & system. Defragment them for a start.