You get a HTTP 413 error when trying to upload or attach a document to an existing entry.
Error message dialog
1.Open the IIS Manager on the server where Devolutions Password Server is hosted.
2.Expand the tree view and select the Devolutions Password Server web application name and open the Configuration Editor in the Management section.
3.Select the value system.webServer/serverRuntime in the Section drop down menu. Then, increase the value of the uploadReadAheadSize parameter. This value is in bytes so if you want to load a 50MB file, you have to change the value to 51200.
IIS Configuration Editor
For more information about these settings, you can consult this web page https://www.iis.net/configreference/system.webserver/serverruntime