@Slayer:
How are you starting the game?
with BepInEx's start script?
Valheim.exe directly?

If you start Valheim though steam (or with this steam://rungameid/892970) and steams launch options for VH only contains "-console" it should work.

Take a luck at "%USERPROFILE%\AppData\LocalLow\IronGate\Valheim\Player.log" and see if it contains anything regarding console or startup parameters in general (dunno what to look for).

You can also use eg. Process Explorer[learn.microsoft.com] or Process Hacker[processhacker.sourceforge.io] to verify what VHs actual starting command line was while the game is running.

Originally posted by Gunnar Hurtya:

Never done it myself, but don't you have to type in " I am a cheat" to get the console functions to work?

no you don't. you need to open the console first and then type "devcommands" to enable the cheating commands.
There are plenty other commands that work just like that (without devcommands).

Originally posted by Doom Shroom Enjoyer:

Go to your properties and launch options then type -console

he did that. or explain yourself better please ("your properties"? I guess he's a human mammal, 1,5 - 2m in height and so on. can't find any launch options there). ;-)

Originally posted by ArcyPawel:

You need to find folder with your save file and make yourself Admin

What?! And no never!
And what is "make yourself Admin" supposed to mean?

1. Use sth like NTPASSWD to hack windows and give himself adminrights? I'm pretty sure he's already got those.
   
2. Set the save game folder so only admins can access it? Makes no sense.
   
3. Start the game with elevated rights? No!
   
4. What else?