Upvotes?

[Arithmetic]

how come i cannot like or upvote comments??

[Joseph41]

I don't know, but many forums have a system established whereby some functions only become available after you have posted a certain number of times. This may be one of those cases.

(But I will emphasise here that I don't know.)

[heids]

Were you signed in to your account when you tried?  Guests can't upvote.

[alondouek]

You were most likely on a board that does not have voting privileges enabled (for example, the exam results discussion board, or the buying and selling boards). In most academic boards, voting privileges should be enabled (such as in this one).

You should, for example, be able to see the voting options on posts in this thread (at top right, next to where you'd click to quote someone's post). Please let me know if the option is not there.

[Clockwork]

If I remember correctly, somebody has to upvote one of your posts before you can start voting on posts.

[achre]

Just on the topic of upvotes, is there any way to see more than just the first 5 alphabetical-order usernames that have voted for a particular post? I may have asked this before, I really don't remember.

[Zealous]

I don't know, but many forums have a system established whereby some functions only become available after you have posted a certain number of times. This may be one of those cases.

(But I will emphasise here that I don't know.)

Yep. I believe you have to hit either 5 or 10 posts before you can up vote iirc. Of course provided you are in a thread where it is enabled.