Lotusberrysiyois it a specific server or any stv in generalI don't fully understand what you mean by specific server. This only happens when I'm opening up a stv demo in console, whether it's my own demos or those of invite players. I don't have a specific server? It's just stv demos in general, I guess.
Do you use a current cfg for your binds? Do you have a ctap jump script that uses spacebar for an alias?
Before doing the next two sentences after this, make sure you unbind whatever is bound to +jump and unbind space too:
What happens when you try bind space spec_prev? Or do bind SEMICOLON +jump and go into spec and try it?
You mention here:
unbinding +jump from my mouse wheel up and down
So I am guessing this is the culprit since the +jump bind also is the same bind used in spectating
It's probably running into an error because you're trying to rebind space while spectating but I'm confused because this error shouldn't show up at all. Before trying a reinstall just reset keys to default before loading into a stv and it would probably fix.