Attaching dotMemory freezes application and shows no data in graph

JetBrains dotMemory 2023.1 Build 231.0.20230404.122145 built on 2023-04-04
dotMemory 2023.1.20230404.122145

Hi!

Does your application use Server GC?

Could you please collect logs for us:

• Close standalone dotMemory.
• Clear %temp%\JetLogs folder.
• Go to dotMemory installation folder: %localappdata%\JetBrains\Installations\dotMemory[N]
• Using Windows command-line start dotMemory with arguments: dotMemory.UI.64.exe /LogLevel=Trace
• Start configuring a profiling session (select Profiling section, choose your process).
• Press Ctrl+Shift+Alt+F11.
• In the Expert options dialog window, select the Enable logs checkbox.
• Type 3887751438631 in “Log mask” field or enable the next checkboxes: Com, Api, Bridge, Snapshot, MetaDataGt, GcCb, GcReferencesCb ,ClassGt, FieldResolverGt, ClassRecoveryGt, MemoryDumpGt, AppDomainRecoveryGt, ThreadRecoveryGt, ClassGt, GcAllocationsCb, MemoryAllocationGt
• Click Save.
• Run the profiling session.
• Reproduce the issue.
• Detach from the process.
• Close dotMemory.
• Look for the logs in the 'JetLogs' folder.

You can upload logs to our ftp.

2024_03_12_WDiDC5NnSaixpcN34q4k2Q upload id

GC settings:

    "configProperties": {
     "System.GC.Server": true,

Just an FYI: dotTrace works fine with the same process.

Hello Sean,

This issue occurs because dotMemory triggers a full GC on attaching to the process. The profiler core initiates a full GC immediately upon connection since otherwise there would be no counters displayed in the UI until the first garbage collection event occurs.

Updates to GC heaps happen only under the profiler at the points when GC is started or finished. Therefore, executing this type of GC is strongly necessary to display correct UI information. The profiler uses for the heaviest type as it is the only way to obtain the necessary data.

A full GC can take a long time in the case of server GC. This is why you are having such UI issues right after attaching or detaching. You may also encounter some UI issues when getting a snapshot and also on each GC if it takes several seconds. Usually this effect is not so noticeable if the server GC is turned off.

Hi!
I have a very similar - if not the same problem - with our software. As soon as I I start profiling our software, the application freezes and dotMemory doesn't track anything. Even detaching doesn't seem to work properly. At least our software is still frozen.  But I'm able to click kill the process.

I'm using

JetBrains dotMemory 2025.2 Build 252.0.20250812.71120 built on 2025-08-12
dotMemory 2025.2.20250812.211931

A log was created using “Log mask” 30276030767399. I used the mask given above and added the missing options. It has upload id 2025_10_28_H99fKk8MoLe8QYNuRUxoBR.

Hi! 

Do you have any antivirus software installed on your machine, such as Sophos Antivirus?

Hi Anna!
Wow, you hit the bull's eye! I have Sophos Antivirus installed on my machine.
If you think, that Sophos Antivirus could be the issue, I'll have a chat with our IT department. 

This is a known issue.

They will probably fix it in one of the next releases.

You can try to exclude dotMemory from Monitor Domain Controller Events and/or Hollow Process policy as a workaround, it helped some people to resolve this issue.

Thank you very much for your help!

I'll talk with out IT then and ask them to please try to exclude dotMemory from Monitor Domain Controller Events and/or Hollow Process policy.

Thakn you very much! :)