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I tried share data without success.

The problem "slow start" is random and happens about 1 from 5 starts. Its not specific to version 59.0.2 because i observed it with earlier versions since quantum. No plugins. 4-5 Session tabs. profile mainly default settings except: - redirected cache to local disk - different performance settings

I was looking for ideas how to debug this case. The profile is redirected to a file share. I can see parent.lock but no further activity in the profile directory in case of a slow start.

I just experienced a "slow start":

parent.lock is written immediatly after 4 minutes cookies.sqlite-shm and cookie.sqlite-wal after 7 minutes Firefox starts.

However it seems to be a network-config problem at our site. In the same time Microsoft Word blocked for about 3 minutes after closing a document on this network drive. Browsing the drive with explorer or opening text files from it stays snappy during this "blocking time". It affects so far Firefox and Office.

Thanks for the Update. Since you believe it is Server sided please mark this as solved with Your Answer.

The Problem is the filer definitely.

At random times there is no problem write files or read, but on delete the explorer may block up to 5 minutes.