I am noticing a delay of 5 to 15 seconds when printing using the DYMO Label Web Service starting this morning, 4/23/2018. This happens on multiple PCs on all browsers. On a Mac it works fine.
The log at %LocalAppData%\DYMO\DLS8\DLSWebService.log seems to show the delay. I don't see any errors in the Console beyond the usual Synchronous XMLHttpRequest on the main thread is deprecated warning.
DYMO.DLS.Printing.Host.exe Information: 0 : PrintLabel: DYMO LabelWriter 450 Turbo
DateTime=2018-04-23T17:08:34.9541652Z
DYMO.DLS.Printing.Host.exe Information: 0 : Loading barcode lib from C:\Program Files (x86)\DYMO\DYMO Label Software\MDYMOBarcode.dll
DateTime=2018-04-23T17:08:50.1456872Z
DYMO.DLS.Printing.Host.exe Information: 0 : Utils.CreateLabelPrintParams(): printParams == null, creating default printParams based on printer type
DateTime=2018-04-23T17:08:50.1547276Z
Status for job sent to printer DYMO LabelWriter 450 Turbo i False
DYMO.DLS.Printing.Host.exe Information: 0 : CheckServiceStatus
DateTime=2018-04-23T17:08:51.3098746Z
DYMO.DLS.Printing.Host.exe Information: 0 : GetPrinters
DateTime=2018-04-23T17:08:51.3269198Z
I tried updating to DLS8Setup.8.7.exe but this did not help.
I broke out Procmon and got to the bottom of this.
It appears to be due to the Dymo Label Service querying 128.30.52.100 (hans-moleman.w3.org) every time it was fed a label to validate its schema. We were not being rate limited by this service until today.
Setting an outbound firewall rule against this IP address for the DLS service executable fixed the issue.