While opening a project in 800Xa 5.1,getting an error like failed to read file from FSD. What could be the reason?
FSD cache will be Present in OPERATEITTEMP folder.
In Which machine are you facing the Problem - Server or Client?
These errors may happen if your FSD cache data has got corrupted. If the Problem occurs in Client machine, just disconnect that particular Client and add it back through Configuration Wizard. If it occurs in Server, delete system and create/restore new system.
Is this problem happened during first time opening of the project from that specific node?
When the project is opened for the first time, system fetches it from aspect directory (using FSD service) and caches the file in 'FSDCache' folder under 'OperateIT temp' folder of the particular node. So during subsequent opening of the project, it uses the local cached copy.
If the problem is encountered while first time opening the project from that particular node, then check the status of 'File Set Distribution' service in service structure and make sure that it is in 'Service' state.
In other case, there are chances that FSD might get corrupted, so disconnect and re-connect the node (if it is client) or sometime deleting the FSDCache folder may also work.
Some files related to CBM is stored in FSD; probably one or more files are corrupt.
I suggest contacting your regional ABB support center and ask for help. In some cases; reloading 3rd party HWD files or sometimes the whole AC 800 Connect system extension may resolve the problem.
Removal and reloading of system extension requires assistance from official ABB support staff (do not try yourself unless you have a written statement from the vendor of the system extension on how to proceed).