DTLS_CLIENT_ERROR, AP doesnt Join with the WLC

[pwc_mexico]

hi Everybody

Some weeks ago i have been had some issues with some APs and in all case i ve seen the same next message error

DTLS_CLIENT_ERROR: ../capwap/base_capwap/dtls/base_capwap_dtls_connection_db.c:2214 Max retransmission count reached for Connection 0x86B4AE4!

I think that maybe the issue is on the WLC because i have some ap´s with the same message, 

We have implemented WLC 5508 and AIR CAP 3600 and 3700 access points

The WLC version is 8.0.110.0

In advance , thanks for your help

[Gustavo Novais]

go to the WLC 

Management

Logs

message logs

and carefully look for this error 

*spamApTask3: Sep 25 16:24:22.587: %LWAPP-3-LICENSE_ACQUIRE_ERR: spam_lrad.c:489 Failed to acquire license from the licensing module, maximum APs Joined 55/55.

it worked for me the maximum number of AP was reached.