Cities Skylines - An Error Occurred Object reference not set to an instance of an object

What to do when you get "An Error Occurred Object reference not set to an instance of an object" Details: No Details - in Cities Skylines. It took me several hours to figure out that it was pretty simple.

You are going to need this MOD:
Loading Screen Mod Revisited

IF THIS VIDEO DOES NOT HELP TRY:
1. Xcatcher or NullReferenceCatcher
AND
2. Extended Error Reporting
Other solutions:
3. Click on “zoning” if there’s a building with no zoning squares under it, DELETE it! That’s what’s causing the problem. I also get this error with Rico plops from @michaeldonato7709

Also, see my series on:
Railway 2 Train Networks - Railway Replacer Tutorial Series [S01]
Remote Japan - Make your own map with street maps overlay and satellite imagery [S02]
Walkington D.C. - 9-mile-long Plazas and Promenades [S03]
Rural Towns - Connecting towns around a stockyard [S04]
MegaCity - 500k population 100% perfect traffic flow [S05]
MiniBuild Northwest - Small population builds for better game performance when detailing [S06]
Cities Skylines Mod Tutorials - Playlist [P01]
Cities Skylines Tips and Tricks - Playlist [P02]

See my assets, mods, and collections on the Steam Workshop:

[Bonnie]

I'm getting the "Object reference not set to an instance of an object error, with a window that doesn't close. It happens when I try to drop the airport, not a modded one. And it started happening right after I linked Paradox. I unsubbed everything, and it's still happening. I can't believe they want eighty something dollars for the CS2 when they can't even get the first one right. They just allow any ole mod.

[TrentosaurusRex]

I don't have any missing or failed assets and I still get this error when starting a new city in a custom map from the workshop. I cannot click the error window away it just keeps infinitely popping back up. Enabling the "Try to recover from missing networks" option in the Loading Screen Mod allows me load into the map with no errors but all then all the outside connection roads are missing or deleted when I load in. The map I'm trying to use is South Lake Tahoe by benben84 and I have all the required assets downloaded and enabled.

[darklightning]

Thanks, it helped! I gave up trying to solve the issue myself and found your video at last. It's a simple lifehack, but a great relief after months of struggle.

[madjodnto]

I was getting this error!

Click on “zoning” if there’s a building with no zoning squares under it, DELETE it! That’s what’s causing the problem. I also get this error with Rico plops

[LEBIKOMO]

素晴らしい仕事です！
Awesome video! Every Japanese CSL user should see this!

[Bipuz]

I have a problem when I enter city skylines, I can't see the cursor from the mouse, but only in that game everything else works normally, can someone help me i have game on epic games

[rdswayne]

I deleted a object from my workbench but not Form my city (some weird round tower) and now i have this error, i wanna find this aaset / Objekt and download it again, how can I find it?

[Martinwilhelminus]

I get this error without using mods. It happens when i adjust busline to have more verhicles. Anyone any ideas? Im playing through the pc game pass not through steam

[cykarim]

i didnt add the assets in "Assets that are missing" i just deleted the object of it, and it didnt work

[International_union_official]

Very haven type video this video helped my a lot Thx!

[Jiyeonieeee]

I got this error when I first opened a map

[ZEBRAFSH]

do u know how to fix the grey button to make a new game i just installed cities skylines on epic games

[exammaster]

I have only 2 mod 81 tills and tmpe v11 but show error any suggestions

[shakal]

idk if you still respond to these, but if you do, im getting this error but i have all my mods turned off, so i have no clue what could be causing it.

[gordon]

reference not set to an instance of an object

[spinykinghhh_]

I get this when i try
to Place the airport

[neodymium]

What do I do if I have a failed asset?

[bananaface]

Hi. I am having this issue but only when I use the 81 tiles 2 mod. I don't have any other mods enabled apart from harmony. Any ideas for a fix?

[exammaster]

I dont used any advance vahical but still show this eeror

[markknudsen]

I'm having the game crashing after selecting a map.. you having similar issue?