Hello,
We have the exact same issue. Real story though, it doesn't only appear on RDS. It appears when using the system directly as well, or so it appears. Get a whole bunch of different ESENT errors but mainly the same as below.
This is now happening on multiple of our client systems and I've literally exhausted every option possible.
Did you find a fix for this? @Ben
taskhostw (42936,D,0) WebCacheLocal: An attempt to write to the file "C:\Users\username\AppData\Local\Microsoft\Windows\WebCache\WebCacheV01.dat" at offset 14188544 (0x0000000000d88000) for 32768 (0x00008000) bytes failed after 0.000 seconds with system error 1453 (0x000005ad): "Insufficient quota to complete the requested service. ". The write operation will fail with error -1011 (0xfffffc0d). If this error persists then the file may be damaged and may need to be restored from a previous backup.