Just seen this message and was going to suggest a change to one of the settings. Microsoft did some security changes to the .NET framework and Googling found a suggestion for the problem of connecting and timeouts. The error you are getting now is of course something else.
Are you getting the error message as soon as you try and run the installer, or does it get part way through?
Edit: Can you try downloading the file DvrOnTimeSetup 1.0.6.zip from here:
https://drive.google.com/drive/u/3/folders/1oGye2AI8d9DaYdskX2nurjdcfiU7KC68 and install that version, that hopefully should install all okay and get you working again. Then stop the service, download DvrOnTime 1.0.7.zip and extract those files over the existing ones in C:\Program Files\DvrOnTime which gets you back up to the latest version.
Once up and running, if you are getting the same timeout message:
1) Stop the service
2) Open Notepad as an administrator by right clicking Notepad and open as administrator
3) Use File - Open and navigate to C:\Program Files\DvrOnTime and use the open filter to look for all files and then open DvrOnTime.exe.confg, this is an XML file
4) Modify as shown below, we are adding a setting called TransparentNetworkIPResolution=False to the database connection, then save the file and restart the service.
Code:
<setting name="DatabaseConnectionString" serializeAs="String">
<value>Data Source = (LocalDb)\MSSQLLocalDB;Initial Catalog = DvrOnTime; AttachDBFilename=%Path%; TransparentNetworkIPResolution=False</value>
</setting>
Hopefully the configuration change will resolve the timeout issues.