Blank PDF preview when Print and Download Prevention Manager is enabled
Posted by Zachary Wick (M-Files) on 02 July 2019 07:10 PM
Version 1.0 | Last Updated 5 March 2019
This issue occurs when the Print and Download Prevention Manager is enabled and you try to view a file that is larger than 10.5 MB. What is attempting to be done is the file is being converted in the background into PDF format, but there is a built in limit inside of M-Files to not convert files that are larger than 10.5 MB. What occurs is that the file is not converted and a blank preview is provided instead.
Here are the steps needed to get a preview returned
- Make sure P&DL is set up and enabled and working as intended on smaller files first. This may require a vault offline/online and also a log out/log in. Make sure that the module is working first just so we know we are starting from a good space.
- Put the following registry in place. The value below will increase the size of PDF processing to 50 MB. This is only necessary for older versions of M-Files. For newer versions please see the Configurations à Advanced Vault Settings à PDF Conversion section of the M-Files Admin GUI.
- Restart the M-Files Server service so it is now using the new registry settings we just put in place.
- Now go into the following location "C:\Program Files\M-Files\Server Vaults\[nameOfVault]\". There will be a folder there called ViewerFiles. Delete this entire folder. This folder contains PDF previews that are generated by the system when someone requests a file. Even if we delete the folder, it will just be generated again when someone requests a preview of a PDF file. This is to make sure we don't deliver up blank PDF previews from the server.
- Now go to each client that is having issues previewing the files and clear the local cache with: Alt button --> Settings --> Clear Local Cache --> Delete All button --> Finish button. Even if nothing is listed, please make sure to click the button sequence. This is to make sure we don't deliver up blank PDF previews from the client.
After this was done, we have confirmed that large PDFs (>80 MB) that were previously not displaying previews, will now display previews as intended.