Getting "error occurred when processing symbol file" error in almost every build

[john-blackburn]

I'm getting the following message in most of my builds

Error message: Error occurred while processing symbols file mydll.pdb

:

jetbrains.buildServer.ProcessTimeoutException: Timeout exception: the process did not produce output longer than 90 seconds; Process: "C:\Program Files (x86)\Windows Kits\10\Debuggers\x64\srcsrv\srctool.exe" -r mydll.pdb

I have about 100 PDBs to index and typically 97 or so will work fine but maybe 3 will fail with this error. As it says it seems to be a timeout thing, not sure why it is taking so long but is there a way to increase this timeout?