I am connecting to Tivo Roamio over Wifi on local network. When using cTivo, it is able to connect to the Tivo enough that it shows you a list of all the shows on the Tivo. The error occurs when you try to download a show from the Tivo, then the cTivo keeps getting "Could not connect to the server" errors. Here is a sample of a log file for cTivo (sorry, I couldn't figure out how to attach a file).
2018-09-02 11:33:38:270 MTAppDelegate>applicationDidFinishLaunching:@216>Starting cTiVo; version: 857
2018-09-02 11:33:38:428 MTAppDelegate>validateDirectoryShared:isTempDir:@626>Creating new temp directory at /var/folders/02/0fx20kr17xb7xkz00126d7080000gp/T/ctivo
2018-09-02 11:33:38:568 MTTiVoManager>netServiceDidResolveAddress:@1719>Got new TiVo: Master Bedroom at 192.168.1.181
2018-09-02 11:33:38:570 MTTiVo>updateShowsForRange:@609>Initial loading from TiVo Master Bedroom at URL
https://DVR-E267.local./TiVoConnect?Command=QueryContainer&Container=%252FNowPlaying&Recurse=Yes&AnchorOffset=0&ItemCount=15
2018-09-02 11:33:44:045 MTTVDB>tvdbURLSession@108>Establishing Session
2018-09-02 11:33:44:296 MTTVDB>tvdbURLSession@123>Cannot establish session with TVDB
2018-09-02 11:33:50:665 MTDownload>launchDownload@1374>Starting 4 download for Meet the Press: Sen. Amy Klobuchar; Sen. Dan Sullivan; Andrew Gillum (Master Bedroom); Format: 1080p; Skip commercials; Keep after iTunes;tivodecode-ng; Program Stream
2018-09-02 11:33:50:706 MTDownload>launchDownload@1566>Starting URL
http://dvr-e267.local.:80/download/Meet%20the%20Press.TiVo?Container=%2FNowPlaying&id=64533 for show Meet the Press: Sen. Amy Klobuchar; Sen. Dan Sullivan; Andrew Gillum in 0.0 seconds
2018-09-02 11:33:50:738 MTDownload>connection:didFailWithError:@2269>Download URL Connection Failed with error Error Domain=NSURLErrorDomain Code=-1004 "Could not connect to the server." UserInfo={NSUnderlyingError=0x60000005deb0 {Error Domain=kCFErrorDomainCFNetwork Code=-1004 "Could not connect to the server." UserInfo={NSErrorFailingURLStringKey=http://dvr-e267.local.:80/download/Meet%20the%20Press.TiVo?Container=%2FNowPlaying&id=64533, NSErrorFailingURLKey=http://dvr-e267.local.:80/download/Meet%20the%20Press.TiVo?Container=%2FNowPlaying&id=64533, _kCFStreamErrorCodeKey=49, _kCFStreamErrorDomainKey=1, NSLocalizedDescription=Could not connect to the server.}}, NSErrorFailingURLStringKey=http://dvr-e267.local.:80/download/Meet%20the%20Press.TiVo?Container=%2FNowPlaying&id=64533, NSErrorFailingURLKey=http://dvr-e267.local.:80/download/Meet%20the%20Press.TiVo?Container=%2FNowPlaying&id=64533, _kCFStreamErrorDomainKey=1, _kCFStreamErrorCodeKey=49, NSLocalizedDescription=Could not connect to the server.}
2018-09-02 11:33:50:739 MTTiVoManager>notifyForName:withTitle:subTitle:isSticky:@1401>Notify: Warning: Could not reach TiVo!
Antivirus program may be blocking connection, or you may need to reboot TiVo