<MOD-DIAM>?!? What is this? Where is my diameter symbol? Sometimes when updating SOLIDWORKS, the file locations can get mixed up. This is usually due to running multiple versions on the same computer. SOLIDWORKS will take the file locations for the version that is installed first. Luckily there is an easy fix for this.
The first thing we will want to do is check where SOLIDWORKS is pointing to the file location path for the symbol library file. We will want to go to Tools > Options > System Options > File locations. Under the dropdown for Show folders for: select Symbol Library File.
We will then want to open a Windows Explorer folder and browse to this path. By default the path is in the Program Data folder under your C Drive. This is a hidden folder. So we will want to make sure all hidden files are visible. If you are unsure how to do this, you can use the following link: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files. Once we get to that path you will want to look for the gtol.sym file. This is the file that contains all of the symbols used in SOLIDWORKS. The file should be missing, and this would be why the symbols are not showing in SOLIDWORKS.
We will want to back up a few folders in the Windows Explorer folder, to SOLIDWORKS folder. Then instead of going to the version that is listed in SOLIDWORKS’ File Locations, go to the newest version. In the picture below, I’ve gone to the 2018 version folder. You can see that the gtol.sym file is located in this location.
This is the new location that we will want to point SOLIDWORKS to. We will want to go back to Tools > Options > System Options > File locations. Under the dropdown for Show folders for: select Symbol Library File. We will want to delete the current location and add the new location that we just found.
Once we click OK, and open up the same document we were working on before, we should see the diameter symbols.