I have had this error for a while now and it is makingthe game unplayable I have tried as many solutions as I have found but none have worked like 

Reinstalling

Checking my antivirus 

Unchecking read only on world generation 

Checking file integrity 

Running steach as administrator 

Running it in 32bit 

-useembedded 

-useshellexecute 

Dose anyone have a solution to this it is very annoying not being able to play

Also make sure cloudsync software (dropbox, google drive, etc.) doesnt interfere with the folder.

my bad my specs are 

windows 10

1920 1080 resolution 

intel(r) core(tm) i5-7400 cpu @ 3.00ghz

16G Ram

nvidia geforce gtx 1060 3gb 

antivirus TotalAV

and i did make an exception for the folders in the antivirus 

As described in the linked thread above I expected you to upload the registry-, diagnostics- and output-file here.

As long as you write about making exceptions for Endless Legend folders, did you include an exception for  ...documents/Endless Legend  folder?

Save Files.zipDiagnostics (2021'05'23 @1207'54'').zipoutput_loRegistry.xml  

 g.txt

Have you ever tried launching the game without having your antivirus on at all? Because the error message you posted in your opening post is pretty clear, the game wants to acces a temporary file in your app data folder, but it cant, presumably because some program is accessing it on creation, which most likely is your antivir.