I am working with the MTXCSEM-L. I have Telnet, HTTP, and socket connections working properly. I am trying to upload a new host web page using TFTP Client and getting an access violation error.

You will need to upgrade to 3.10. Here is a link to download 3.10 firmware:

https://webfiles.multitech.com/embedded/socketethernetip/mtxcsem-v310.zip