When attempting to login to ImageManager, an error stating that you cannot connect to ImageManager on localhost:56765, object reference not set to an instance of an object is displayed.
ImageManager 6.0.0.x by default, utilizes port 8080 for some of its internal communication, in some environments, this port is unavailable or heavily used causing ImageManager to display this error.
Change the port ImageManager uses from port 8080 to 8000:
edit the C:\Program Files (x86)\StorageCraft\ImageManager\ImageManager.exe.config file
do a CTRL-F and search for 8080, you'll find the section of this file that says:
<setting name="wcfPort" serializeAs="String">
Change 8080 to 8000
Save the changes to the file.
open the C:\Windows\SysWOW64\config\systemprofile\AppData\Local\StorageCraft_Technology_C\ImageManager.exe_Url_vxqptsrgdhidxdbnghlzykdkkitq2cdy folder
open the next subfolder (6.0.x.x)
edit the user.config file and search for 8080, it may or may not contain another reference to 8080. If it does, replace 8080 with 8000. save it.
Restart your image manager service and you should be able to log into ImageManager.