It is no possible to upload files more then 200Kb
Currently, Plesk does not have feature to manage these settings from the Panel, so you may use the following workaround:
Go to IIS, check the site you want to change settings.
Open the Advanced Settings link in the right panel. Set Connection Time-out (seconds) to a much bigger number. For example, an hour (3600). Close Advanced Settings.
While still choosing your website, click on the "ASP" tab, then expand Limits Properties and set Maximum Requesting Entity Body Limit to 1073741824.
"C:\windows\system32\inetsrv\appcmd set config -section:requestFiltering -requestLimits.maxAllowedContentLength:100000000".
After these actions you should upload files successfully.