%PLATFORM_UCAST-4-PREFIX: --------- TCAM 3750 Switch

 %PLATFORM_UCAST-4-PREFIX:  One or more, more specific prefixes could not be programmed into TCAM and are being covered by a less specific prefix, and the packets may be software forwarded

So what is TCAM ?

Ternary Content Addressable Memory is used in multi-layer switching also know as Layer 3 switching. The switches forward the packets and frames at the speed of the line by using ASIC hardware. Normally switches make there forwarding decisions based on Layer 2. TCAM is used for Layer 3 components and other features such as QOS and ACES ( Access List ). 

Check TCAM and usage of templates being used in the device. 

show sdm prefer ?

!This will show us the templates that can be used in the device to give more resources to one feature or the other. For example the default is the equal resource distribution while the routing gives more resources to Layer 3 routing.

show sdm prefer

! The command without the "?" will show us what we are currently running. 

show platform tcam errors

!Shows us the errors in the tcam table 

Switch#show platform tcam errors
TCAM Memory Consistency Checker Errors
--------------------------------------
TCAM Space          Values      Masks     Fixups    Retries   Failures
Unassigned               0          0          0          0          0
HFTM                     0          0          0          0          0
HQATM                    0          0          0          0          0

show platform tcam utilization  <interface> or <asic>

!show the current utilization of TCAM for a specific ASIC or in general. 

When seeing this error it could be likely you need to change the SDM template to something other than the current or that there was errors occurring between major routed links such as an adjacency drop.