Dawn of the Tiberium Age mod for C&C: Tiberian Sun

Could you elaborate, give more details?

Easy, especially on Covert Revolt (previous missions are often much less standardised about difficulty) is meant to roughly match Red Alert 1 or Tiberian Sun's normal campaign difficulty

It wasn't as thoroughly tested as higher difficulties; statistically, it's meant to usually send half as much stuff at you as Hard and a third of what Brutal does

Yes I've tried moving onto the cells where the crate would be, and no currency or upgrades given to the unit moving over where it should be.

There's 1 mission where your supposed to collect weapons for the Commando for example. I moved to the location it stated it would be, and went to the exact position I'd seen other people (on Youtube) collect the weapon upgrades there, but for me nothing happened. Luckily on that one, there was enough random enemies around to get the Commando up sufficient ranks. Took some work though.

In the case of C12, it made a major difference tactically, as without the money crates it made even attempting a base a waste of time. Luckily even without them, I managed to make 2 mechanics, so got that mission done, with some work.

Video of it occurring in mission B12:

(Jump to 25:14)

Covert Revolt campaign explores one ex-Soviet area in depth while Mayday skims over another

In DTA canon, there isn't just a power vacuum where USSR used to be with constant chaos, there is an array of different republics with their own militaries and politics that Allies themselves helped install simply for stability's sake and which GDI monitors and to a limited extent cooperates with

These ex-Soviet states sometimes use former Allied surplus and sometimes old Soviet weaponry depending on their capability to maintain it, with much of old equipment also going into 3rd world countries (like Serunda in PTTP, where SLF has notably more jury-rigged arsenal than other playable factions)

Said ex-Soviet states usually have no political will to challenge status quo, with usually corrupt heads of state benefitting from it, and if they did so openly, you can actually experience how drastically skewed the odds are in GDI's favour on your own skin in CR route C - any statelet that incurs GDI's true wrath is almost certain to be toppled and reforged into one that doesn't stir trouble before it even has time to form any sort of bigger bloc

CD6 is where THE difficulty spike starts
It has no such things as "easy" or "normal" difficulties and starts at "hard" through "brutal" to "ultimate" for a reason, that being Creeping Destruction is deliberately intended to be very challenging, unforgiving campaign, the last 3 missions specifically tuned into filling the masochistic desires a highly experienced and bored player may have

With enough effort I can assure it's doable even on "ultimate" also nowadays - it demands to lock the ztype in and run defense optimally: with strong economy, rapid but well chosen production and effective micromanagement all at once

Production-wise, I recommend flamers and initial mammoth arty to lock the western chokepoint, and elsewhere employ mammoth tanks, V2 launchers, tesla coils and flame towers; some players also enjoy using yaks or MiGs; defend the blue tiberium at all cost and run 1-2 service depots to cycle the mammoths

Here's a "cheat", decreasing game speed will make it easier to manage everything ^^

That's not the point, I can't seem to build units fast enough. When I try build Weapons Factory or so, I can't build base defense.

Slam a barracks as soon as you can on the frontline (every front each ideally), that's precisely what they're made for - stuffing the hungry maw of frontline with disposable meat from a new production queue until the real deal arrives

The main limiter of infantry are that when hard counters are present you'll be bleeding credits like crazy on replacements, apart from rifle infantry where the bleed is more muted at expense of limited ability to actually shoot back (and infantry's other usual shtick is hitting very hard for given cost)

Speaking of the real deal - you should get a second, blue tiberium adjacent factory built very soon, maybe a third - it's mammoths and V2s that are getting the job done when Nod's artillery legions are involved, while defences act as backup - pick up recon/inf/tank flankers or stragglers, and cover for your battered mammoths retreating to repair or get fire support

Oh, and by the way, you have MCVs for a reason - if you insert an order for one or two between the early batches of combat vehicles you'll speed up your base defense rollout and any expansions or replacements for production structures - every new conyard/factory/barracks is essentially 0.75x modifier to build time, stacking multiplicatively