When ExtendSim launches it requires the loading of certain files and it expects that those files have been installed at specific locations. If needed files don’t have the correct permissions, or if ExtendSim can’t find the files, ExtendSim will not launch properly.

Common situations that cause problems are:

• Someone from your IT department or an Admin installed the user-modifiable files in a folder under their account rather than in a folder accessible by the end user. Or, they tried to launch ExtendSim from their own account.
• The folder containing user-modifiable files does not give the end user or ExtendSim the correct permissions.
• The folder that contains user-modifiable files has been moved after installation, so ExtendSim is looking for files in the wrong location.

If ExtendSim issues error messages such as “Documents folder not found”, “lp_solve[0] Error…system error code:2”, or "Unable to load DLL" as it tries to launch or gives a similar error message when end users try to open model or library files:

• By default, user-modifiable files (such as examples and libraries) are installed to the UserName\Documents\ExtendSim folder on the C drive. Be sure that ExtendSim folder has been installed to the default path, not to some other drive, such as the D drive or to OneDrive.
• Verify that the ExtendSim folder that contains user-modifiable files is installed in the end user's account (not an Administrator's account) and that the folder is accessible by the end user.
• Check the  permissions for the ExtendSim folder that contains user-modifiable files. Depending on it's location, end users need read/write or full access to that folder so they can open, run, and save models.
• If the ExtendSim folder that contains user-modifiable files (such as examples and libraries) was properly installed to the end-user account, ExtendSim needs to be launched from that account, not from the Administrator's account.
• When you install, you might need to right-click the installer icon and select Run as Administrator. (Even if you are the Administrator, you still might need to do this.)
• So that it can properly open needed files, the first time you launch ExtendSim, right-click the application icon and select Run as Administrator. (Even if you are the Administrator, you might still need to do this the first time you launch ExtendSim.)
• So that ExtendSim will know where user-modifiable files are located, the installer places an ExtendSimDocPath.txt file in the Program Files\ExtendSim folder. If the ExtendSim folder with user-modifiable files files was moved after installation, modify the file ExtendSimDocPath.txt file to indicate the new location.