order to fix
this issue, open Bizagi Studio or Management Console and edit
the Upload Max File Size property located in the Advanced options in
the Environment configuration. Set the value that you require according
to your Business needs.
the value is set, configure the upload size in the IIS.
Open the IIS Manager and click on the Default Web Site. Then, click on
Request Filtering located in the IIS group.
on Edit Feature Settings…
a value at least as the one previously defined in the Maximum
allowed size (Bytes) property.
your IIS Server and then test.