Note: this article concerns MiddleVR 1.x only.

Symptoms

Editor

In the console of the Unity editor you see the following:

Player

In the Unity player logs you read:

DllNotFoundException: MiddleVR_CSharp

Possible causes

- The PATH environment variable is not set or not correctly.

- The DLL file is not accessible.

- The DLL file did not find some of its dependencies.

Solutions

PATH

During its installation, MiddleVR sets the PATH environment variable to indicate where MiddleVR DLLs are stored.

Although they are ways on Windows to immediately start new programs with the modified PATH value, we strongly suggest to simply restart your computer.

Another possibility is that upon installation the installer was not able to modify the PATH. You can fix this manually by following the instructions in “Manually adding MiddleVR to the PATH environment variable”.

In old MiddleVR versions, sometimes the PATH environment variable was not correctly set after installation. As a result, Unity could not find the MiddleVR DLLs. See instructions at “Warning! PATH too long installer unable to modify PATH!”.

DLL not accessible

There are usually two possibilities that could make a DLL file inaccessible.

The first case is just that the file is not located where you expect to find it. Is MiddleVR installed on your computer? Did you manually move files of MiddleVR in its installation folder? Did you install MiddleVR on a network-attached storage system and check that the remote storage is online?

The second case is related to file permissions. A DLL must be executable so please check permissions of the involved DLLs (including dependencies, see bellow).

Missing DLL dependencies

A DLL will fail to load if some of its dependencies are missing (or are not accessible). A solution is often to use a software that will track what DLLs a DLL is trying to open and then to find which one is the culprit. For example, you may have a look at “Dependency Walker”. But before trying such a software, reinstall MiddleVR.