MATLAB Answers


Why do I get the error "MATLAB Web App Server files not found" when starting the Web App Server?

After installing the R2018a Web App Server I try to start it, but get the error:
MATLAB Web App Server files not found. Verify that MATLAB Runtime appears before any installed version of MATLAB in the Windows Path environment variable.


No tags entered yet.



No release entered yet.

3 Answers

Answer by MathWorks Support Team on 25 Jul 2018
Edited by MathWorks Support Team on 25 Jul 2018
 Accepted Answer

In the Windows PATH environment variable, MATLAB Runtime (MCR) must appear before any MATLAB installation paths. Having them the other way around could be caused by a previous installation of the Prerelease version of the Web App Server.
Make sure that MATLAB Runtime (e.g. C:\Program Files\MATLAB\MATLAB Runtime\v94\runtime\win64) appears before MATLAB (e.g. C:\Program Files\MATLAB\R2018a\bin) and try launching the Web App Server again.
1. Go to Control Panel > System > Advanced system settings > tab "Advanced" > Environment variables.
2. Under "System variables", find the variable "Path" and click Edit.
(The Variable value likely contains several paths, too long to conveniently edit in the small field. For convenience, you may find it easier to copy the value to Notepad or a similar editor, edit it there and copy it back after making the changes.)
3. Edit the path so that the path to the MATLAB Runtime is listed before the path to MATLAB.
The path of MATLAB Runtime has the following format:
C:\Program Files\MATLAB\MATLAB Runtime\<version>\runtime\win64
(Version v94 is for R2018a. For a list of versions refer to
The path of MATLAB has the following format:
C:\Program Files\MATLAB\<release>\bin
These are the default installation folders. Your paths may vary depending on where you installed MATLAB and the Runtime.
For example, initially the Path variable value might look like this (MATLAB before MCR):
%systemroot%\system32;%systemroot%;C:\Program Files\MATLAB\R2018a\bin;C:\Program Files\MATLAB\MATLAB Runtime\v94\runtime\win64
It has to be corrected so that MCR is listed before MATLAB:
%systemroot%\system32;%systemroot%;C:\Program Files\MATLAB\MATLAB Runtime\v94\runtime\win64;C:\Program Files\MATLAB\R2018a\bin

  1 Comment

How do I make sure if MATLAB Runtime appears before MATLAB?

Sign in to comment.

Answer by Andreas Neocleous on 2 Jul 2018

It would be nice if you could elaborate a bit more on how to do this. For instance, what would be the name of the variable? I went to the environment variables (windows 7) and there was not MATLAB variables. Then I created one with the "variable name" --> "MATLAB MCR" and "variable path" --> C:\Program Files\MATLAB\MATLAB Runtime\v94\runtime\win64 Then I made another one "variable name" --> "MATLAB" and "variable path" --> C:\Program Files\MATLAB\R2018a\bin.
Then, MATLAB comes before MATLAB MCR because it goes with alphabetical order. And then MATLAB web server gives the same error.

Answer by cui
on 23 Apr 2019

By following the above, my environment variable is set as shown Figure,but it does't work! same error ? my matlab release 2019a

  1 Comment

There are two PATH variables, where one is local and another is global. Please check both.

Sign in to comment.