I've tried installing Script Extender but the program never injected into my MW files. Now when I try to get to my Play menu, I have all these errors and it just crashes the game. I've unclicked all the mods I've tried to install so I don't think that's the problem. I think it must be MWSE. The warnings message I'm getting is

chunk size 10 too big in chunk WEAT_ID in form REGN_ID
max size is 8, data truncated to "0#0000"
unknown sscr_id in ConstructObject
(that line appears three times)
Data Handler: unrecognized form

It's repeated several times and there's various warnings about weather chances not totalling 100% mixed in.

I have no idea how to fix this because all I know is how to unclick mods. I've been looking on tutorials but can't find anything that will help. Could this be a problem with MWSE? It's the only thing I can think of because with the other mods unclicked they shouldn't be affecting the game. I'd greatly appreciate your help.