I was making a character sheet for a friend (4th level tempest domain cleric, protector Aasimar). We were going to select his cantrips and spells, clicked on toll the dead, and the window just showed Error Code: f50fb1ccf2fa44afb5d089f79a4dd688

Is there anything I should do?

I can select other spells, just not Toll the dead.

Edit: also cannot select: word of radiance for some reason

Those spells aren't in the Player's Handbook, they are from Xanathar's Guide to Everything. There are very few spells on the Cleric list that aren't in the Player's Handbook, and the only ones available to level 4 cleric are the two cantrips you mentioned, and the ritual spell Ceremony.

Fortunately you can purchase a single spell for $1.99, you don't have to buy the entire Xanathar's Guide!

Does that player own those spells or are they in a campaign with content sharing enabled?

If the answer is no to both of those, then they do not have access to those spells.

I have Xanathar's, I think its because I have the spell but he doesnt.