Simulink does not start

I run MATLAB on Windows 7. I can start Matlab 2011a without a problem; however, I can't start Simulink, it gives me this error:

MATLAB:dispatcher:loadLibrary Can't reload 'C:\Program Files\MATLAB\R2011a\bin\win64\libmwsimulink.dll'. Caught MathWorks::System::FatalException > What can I Do? I don't have anti-virus and the file exists.

I would appreciate any help

[Jiggly]

I have a trial R2015a release on Windows 7, 64 bit. I can open and run Matlab however when I try to start Simulink I get the busy mouse pointer but no Simulink. I've tried the rehash suggestion below with no effect. I've uninstalled/re-installed again with no effect.

Anyone else encounter this issue?

Answer 1

[Andreas Goser]

Try

rehash toolboxcache

Answer 2

[Luis Arias]

try both options and none worked. Any other suggestions?

thanks!