Error when uploading an ISO

[Justus.bwr]

Hello,
Everytime I try to upload my TrueNAS iso it stops at around 20-30 percent and gives me the following error code:
Error '0' occurred while receiving the document
I have ewnaugh free space on my disk. My User is an Administrator, so there shoulden´t be a problem with permissions.
You can see it for yourself in the attached image. (Sorry my installation is in german)

 

[dsh]

Have you tried directly copying?

just scp to /var/lib/vz/template/iso/

 

[Justus.bwr]

Have you tried directly copying?

just scp to /var/lib/vz/template/iso/

no im new to proxmox. could you tell me how to copy the iso the?