Abl3Book1

a few days ago my 1.14 forge wasn't working but 1.8.9 was working. Now its the other way around its showing a crash report and it says "ERROR Game crashed The game crashed whilst initializing game Error: java.lang.NoClassDefFoundError: cer"

hey sorry i haven't been on my laptop for awhile but i just tryed it and it worked thanks!

Sorry my prtscreen button wasn't working so I had to do it on my phone

https://files.minecraftforge.net/maven/net/minecraftforge/forge/index_1.14.3.html

so i'm new to java and mods and I just downloaded java, optifine, and 2 different version of forge 1.8.9 and 1.14.3. I tried using the 1.8.9 version first for optifine and it worked but when I went to 1.14.3 it said "unable to install java" even though i downloaded it and it said successful then i deleted it and re downloaded it many times and idk what to do. someone please help me