JSI Tip 1123. Event 2021, Unable to allocate a work item.

If you receive the subject event, multiple times, use regedt32 to navigate to:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesLanmanServerParameters

Edit or Add Value name MaxWorkItems, a type REG_DWORD entry, and set the data value to a decimal number that is either 512, 1024, 2048, 4096, or 8192. If you added the Value Name, start with 512, otherwise pick the next higher number.

Shutdown and restart.

If the problem continues, pick the next higher number.

You may want to see tip 1012.