Token security error when changing style order

[EuroBeat2]

I am not sure if anyone had that issue. I have 3.7.0 installed. I recently wanted to change the order of the styles and I received that grave error we all know:

Your submission could not be processed because a security token was missing or mismatched.

If this occurred unexpectedly, please inform the administrator and describe the action you performed before you received this error.

Any suggestion what to do?

Thank you.

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UPDATE:

What is also very interesting that if I click now on the link "inform the administrator" I am getting an additional error:

Not Found

The requested URL /admincp/sendmessage.php was not found on this server.
I checked, there was never sendmessage.php included in original package that should be placed in /admincp directory. There is one in MAIN directory.


It is quite odd behavior. This entire issue of security tokens is really confusing.

PROBLEM SOLVED.
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Apparently I had plugin: Inferno CSRF Auto Protection installed back from ver 3.6.10. I did not disable it in ver 3.0.7. However, after disabling it now, the problem is no longer.

EB