Any web based script will have hard times handling very big file uploads. So if your files exceed in size the usual PHP default setting of 2M, you may experience problems with MyWebFTP while uploading them. Although if you can modify the server PHP configuration, this limit can be extended. There are a number settings that affect file uploading:
upload_max_filesize
the most important setting in this case, as the name suggests, sets the maximum filesize for uploads.
Although file uploads are also affected by a number of other settings:
post_max_size
Sets max size of post data allowed. This setting affects file upload - this value must be larger than upload_max_filesize.
memory_limit
If memory limit is enabled, memory_limit also affects file uploading. Generally speaking, memory_limit should be larger than post_max_size.
max_execution_time
Also uploading large files would require pretty long time so we suggest that this setting should also be extended.