How can I connect different vlans?

[recep_ali_sevim]

Hi, I have network for CCTV and I have many vlans on my system. Now, I will connect other network with Layer 2 and there is a Vlan 10 but I have same vlan on my network. So, I connected access port( Vlan 10) of other network switch from my access port (I gave Vlan 88 name on port).. It has worked for a year but today I can't connect to there... How can I solve that problem? 

[balaji.bandi]

Not sure what was changed, post the interface config, which was connected switch to switch, also port config where the CCTV port connected.

[Georg Pauwen]

Hello,

post a schematic drawing of your topology showing how your devices are connected, where the Vlans are, and where the new 'problem' device is...

[MHM Cisco World]

I think there is STP BLK port can you check it?

[Joseph W. Doherty]

Connecting access ports, using different VLAN, wouldn't be considered best practice, but as you've noted "It has worked for a year".

The most likely cause for this to stop working is something was changed on one side of the connection or the other.  If you at least have NTP active on the devices, at least check is there's been any recent config changes when you show the device configs.