Can't upload images through Manager

Hi, I have used Modx on two different host sites. The current one continues to error when I try to upload images using Modx’s CMS interface. I contacted my hosting support and this is the response:

"I tried to upload a file and saw the same error. When I checked with Process Monitor, I found operation "QueryAllInformationFile" from C:\hosting\webhost4life\member\fredproby\modx\manager\media\browser\mcpuk\connectors\php\Commands\FileUpload.php and the result is "Buffer Overflow".

Would you check with your application vendor and see if they have solution to this?"

This is an issue it looks like in the Modx Manager...
In order for Modx to work as a CMS, this function is necessary. I’ve not had this problem before. Does anyone know what the issue is?
Thanks!