This message appears when the plug-in is too slow in preparing the check and the timeout for client/server communication is exceeded. In other words, the plug-in gives up and displays the message that it's taking too long.
The solution is to get a faster computer so the Acrolinx plug-in can run as fast as it was designed to.
A workaround is to increase the timeout setting for client server communication.
To increase the timeout, create the registry value “IncreaseTimeOut” (DWORD type) in “HKEY_CURRENT_USER\Software\acrolinx\Plugins“ and set it to “1”