I had Installshield project files on my server so that myself and another colleague could work on installers together. All of the source files were also on the server. Everything was working just fine. However, when I went to use it this week I cannot see the X:\ where the files are stored. The files are there and I can see them in Windows File Explorer outside of Installshield but I cannot see it from inside Installshield.
FYI: I updated to Service Pack 2 this morning. It worked a few months ago on Service Pack 1.
When I click on the project file on my server it says "This project was not found. It may have been deleted...."
Here we would like to know, what edition of InstallShield 2018 SP2 you have installed. Is it Installshield 2018 SP2 express? You can get this information from the About dialog. Check the edition is matching with your previous SP1 edition.
Next, what all are the file exist in the X: location. What is your project file name and it's extension. After, opening in Installshield 2018 SP2, is there any file got created newly in that location..something like projectfilename_XXXX.