This error can happen in any of the BizTalk360 sections where Performance Counters are used and there is some problem with them.

Category does not exist.
System.InvalidOperationException: Category does not exist. at System.Diagnostics.PerformanceCounterLib.CounterExists(String machine, String category
System.Diagnostics.PerformanceCounter.InitializeImpl() at System.Diagnostics.PerformanceCounter..ctor(String categoryName, String counterName,
instanceName, Boolean readOnly)
at System.Diagnostics.PerformanceCounter..ctor(String categoryName, String counterName,

This problem is related to disabled Performance Counters. To identify if this can be the reason why you are getting this problem, run this command in an elevated command prompt:

lodctr /q:PerfProc

If the problem exists, the result of the command should look like this:

Performance Counter ID Queries [PERFLIB]:

Base Index: 0x00000737 (1847)

Last Counter Text ID: 0x00002160 (8544)

Last Help Text ID: 0x00002161 (8545)

[PerfProc] Performance Counters (Disabled)

DLL Name: %SystemRoot%\System32\perfproc.dll

Open Procedure: OpenSysProcessObject

Collect Procedure: CollectSysProcessObjectData

Close Procedure: CloseSysProcessObject

In this case, you can try to enable the performance counters by running the following command:

lodctr /e:PerfProc

After the counters are enabled the problem should go away. To investigate why your performance counters got disabled, search you servers Application Event Log for the source PerfLib.