Hello,
Dynmap won't render any modded block even after a pass of BlockScan ; modpack Ragnamod.
LostBot on Discord was able to reproduce the issue.

Edit : renderdata folder IS populated after BlockScan pass.

• Dynmap Version: Dynmap-3.4-beta-3-forge-1.16.5

• DynmapBlockScan Version: DynmapBlockScan-3.4-SNAPSHOT-forge-1.16.5

• Server Version: forge 1.16.5

• Pastebin of Configuration.txt: https://pastebin.com/B1Hq8mY3

• Server Host (if applicable): Selfhosted on dedicated

• Pastebin of crashlogs or other relevant logs: Log first start with BlockScan : here ; Log next start BlockScan moved out : here

• Other Relevant Data/Screenshots: Modpack Ragnamod VI

• Steps to Replicate:

• Install fresh Ragnamod VI modpack server.
• Add Blockscan and dynmap mods.
• Start server a first time with BlockScan
• Stop the server
• Move remove BlockScan
• Start the server
• Start fullrender
• Map rendered without modded blocks

I figured out that some mods are incompatible and trigger the error.

I'm still investigating on which ones.

After many hours of trial and errors, I finally found out the culprits:
Environmental Core and Twilight Forest seems to be incompatible !

thanks! I will create a list and add those to said list.

https://github.com/webbukkit/dynmap/wiki/Mods-found-to-be-incompatible-with-Dynmap-and-Dynmap-blockscan
added a list to the github for others to read. As this is out of our control I am going to go ahead and close this issue for now.