A little while ago I ran into an issue when trying to add or edit any node and I have no idea what is causing it.
Adding node error reads:
Editing Node error reads:
I cant to seem to find answers on Google or THWACK and not being super server savvy in not sure where to go beyond stopping and starting services.
There is a solution in thwack only, which may help you to find the solution. I have tried on your behalf . They have tried some scenarios and finally after contacting the Support, as per their suggestion, you need to tweak the settings and then issue will be resolved.
The resolution: They worked with Solarwinds support and changing the maximum worker processes from 5 to 1 on the Solarwinds app pool resolved the issue.