As any user of Orion 8.x can attest the problem with the error "Cannot load network map..." can be exasperating. I saw somewhere in Thwack that this was associated with a memory leak in the 'dllhost.exe' process. If you kill the process then refresh all is well.
I also saw a supposed work around to modify the COM+ pool - which did not work at my site. It only made things worse.
In any case we started to use the following command from a priveledged command prompt to kill the process which then will start a new one.
taskkill /s \\ /IM dllhost.exe /FI "USERNAME EQ SOLARWINDS_WEBSITE"servername