I tried making a 6 Artificer/6 Wizard character recently and realized she had spell slots much higger thab what she could learn from leveling up. The rules say a wizard can copy a spell into their spellbook so long as they have spell slots for it, but DnDBeyond won't let me access any spells via spell scrolls. Is this a bug? How do I work around it?

Quote from Tessla_the_Kitsune >>

I tried making a 6 Artificer/6 Wizard character recently and realized she had spell slots much higger thab what she could learn from leveling up. The rules say a wizard can copy a spell into their spellbook so long as they have spell slots for it, but DnDBeyond won't let me access any spells via spell scrolls. Is this a bug? How do I work around it?

That is not quite what the rules say about copying spells into your spellbook as a Wizard. The actual rules do not reference spell slots. They say you can copy a spell into your spellbook "if it is of a spell level you can prepare". A character with 6 Wizard levels and 6 Artificer levels can't prepare level 4 spells, so they can't copy level 4 spells into their Wizard spellbook. This character would have a level 4 spell slot, but as noted in the section on Multiclassing, it can only be used to upcast spells of level 3 or lower since you can't prepare level 4 spells.

Quote from wagnarokkr >>

The actual rules do not reference spell slots. They say you can copy a spell into your spellbook "if it is of a spell level you can prepare". 

 
It does actually reference spell slots.

2014 Wizard - Preparing & Casting Spells

You prepare the list of wizard spells that are available for you to cast. To do so, choose a number of wizard spells from your spellbook equal to your Intelligence modifier + your wizard level (minimum of one spell). The spells must be of a level for which you have spell slots.

2024 Wizard - Prepared Spells of Level 1+

You prepare the list of level 1+ spells that are available for you to cast with this feature. To do so, choose four spells from your spellbook. The chosen spells must be of a level for which you have spell slots.

The number of spells on your list increases as you gain Wizard levels, as shown in the Prepared Spells column of the Wizard Features table. Whenever that number increases, choose additional Wizard spells until the number of spells on your list matches the number in the table. The chosen spells must be of a level for which you have spell slots.

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The rules on scribing are

2014 Wizard

When you find a wizard spell of 1st level or higher, you can add it to your spellbook if it is of a spell level you can prepare and if you can spare the time to decipher and copy it.

2024 Wizard

When you find a level 1+ Wizard spell, you can copy it into your spellbook if it’s of a level you can prepare and if you have time to copy it.

So, yes, there is a reference to spell slots and if this was the only rules relevant text then the OP should be able to copy the higher spell. However, the issue is the Multiclassing rules that you mention.

2014 Multiclassing - Spellcasting

You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class. If you are a ranger 4/wizard 3, for example, you know three 1st-level ranger spells based on your levels in the ranger class. As 3rd-level wizard, you know three wizard cantrips, and your spellbook contains ten wizard spells, two of which (the two you gained when you reached 3rd level as a wizard) can be 2nd-level spells. If your Intelligence is 16, you can prepare six wizard spells from your spellbook.

2024 Multiclassing - Spellcasting

You determine what spells you can prepare for each class individually, as if you were a single-classed member of that class. If you are a level 4 Ranger / level 3 Sorcerer, for example, you can prepare five level 1 Ranger spells, and you can prepare six Sorcerer spells of level 1 or 2 (as well as four Sorcerer cantrips).

Each spell you prepare is associated with one of your classes, and you use the spellcasting ability of that class when you cast the spell.

So yes, the OP should be adding/scribing/preparing wizard spells as a 6th Level Wizard. 

Yeah, I was trying to condense it a little bit so that I wouldn't have to post a huge wall of text to say exactly the same thing.

Quote from wagnarokkr >>

Yeah, I was trying to condense it a little bit so that I wouldn't have to post a huge wall of text to say exactly the same thing.

 
Maybe a better option is to just mention the multiclassing rules and not give false information that the rules don't reference spell slots when they do. My wall of text is for you, to correct you, after all.

Quote from spamandtuna >>

They were discussing the rules for copying a spell into your spellbook, which indeed do not reference spell slots.

Copying a Spell into the Book. When you find a level 1+ Wizard spell, you can copy it into your spellbook if it’s of a level you can prepare and if you have time to copy it.

 

 
But this relies on "what you can prepare" which does.

The confusion of the OP is because the rules on what you can prepare and therefore what you can copy are based on spell slots. Saying it doesn't mention spell slots when the rules on what you can prepare, and therefore copy, actually do only further enhances confusion. It is very clearly what the OP is referring to. Saying it doesn't reference them is only coming across as telling the OP they read it wrong - when they did not. The OP read it perfectly correct - they just missed the extra Multiclassing rules.