Import error - synology NAS

installed on my Synology NAS via Portainer and everything seems to be working fine. when I import my Bitwarden data (tried .json and .csv) I get this error:

<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <style>body{font-family:Arial,Helvetica,sans-serif;font-size:12px;text-align:center}h1{color:#06C;font-size:25px;line-height:60px;margin-top:56px}img{margin-top:40px} </style> </head> <body> <img src="data:image/jpg;base64,/9j/4AAQSkZJRgABAQEASABIAAD/2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQECAQEB AQEBAgICAgICAgICAgICAgICAgICAgICAgICAgICAgL/2wBDAQEBAQEBAQICAgICAgICAgICAgIC AgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgL/wAARCAAzAMgDAREA AhEBAxEB/8QAHwAAAgIDAAMBAQAAAAAAAAAAAAkICgEGBwQFCwMC/8QARBAAAAYCAAUCBQIDAwYP 

i can send the full error log if needed. any ideas?

thanks