Cannot modify any virtual machines in vSphere Web Client 5.5 - Cannot complete operation due to concurrent modification by another operation.

[CMcKown]

This is killing me. All I want to do is add an additional NIC to two VMs. I can't. This is a new installation. I have 5 running production VMs plus the vcenter appliance. Things WERE working fine and just quit working out of the blue.

I can't even "connect" an ISO image to a CDROM.

I tried powering down the VM with no change. (Actually the VM never would even show is was powered off in the client, but since the only power option was "power on" at this point, I assumed it was off.)

I can't modify ANY VMs at all. I have restarted the vCenter Appliance with no change in behavior. Why are we forced to use this horrible Web Client??????

Running 5.5 build 1750787 - Have been pushing to sell hyper-v since the support options for vmware are cost prohibitive for SMB, but vendor for this customer requested vmware.

[farmersWPSD]

I'm having similar issue with hard drives.  Tried expanding one and removing another.

The Web Client thinks the machine is on, but can't access it.  I tried removing drive in regular Client.  Said I need to use vCenter.  vCenter couldn't do it.  After trying a few things, tried regular Client again and I could remove the drive.

[Ajsharma]

TRy any of these KB & see if it fixes the issue.

1) http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=201632...

2) VMware KB: Editing a virtual machine immediately after connecting a client USB device results in an ...

[mahmoudsns]

did u solve it? i ve the same problem and i m trying to solve it.

[anicolai002]

Ran into same problem in a vSphere 6.5 environment. To solve i simply powered off the VM, rightclick and remove from (vCenter) inventory. Browse the datastore, rightclick .vmx file and "register VM". After those simple steps i was able to edit settings.

[mheathg]

This worked perfectly for me. Thank you very much for your comment.

[DineshMahesh696]

Check on any action on Work in progress tab. is any taks are exist. Please Clear all the proceess here and try to edit.