Re: upload my-plugins & forum vanishes
I assume there were files containing code in the my-plugins folder? There is probably some PHP error being triggered. Most production servers write this error to a log instead of displaying it in the browser and then cease execution of the PHP script.
You need to locate and read this log to begin to troubleshoot.
If there are multiple files in your my-plugins folder, then try uploading them one by one until the error occurs. That way you will know which file is broken.