Hi all,

we have big trouble with a new developed website on umbraco v7.5.3 since a few days.

We have the following errors at irregular times in trace log:

     2016-10-17 16:48:44,820 [P1160/D2/T1]  INFO  Umbraco.Core.PluginManager - Determining hash of code files on disk
     2016-10-17 16:48:44,883 [P1160/D2/T1] INFO  Umbraco.Core.PluginManager - Hash determined (took 64ms)
     2016-10-17 16:50:18,889 [P1160/D2/T1] ERROR Umbraco.Core.UmbracoApplicationBase - An unhandled exception occurred
    System.TimeoutException: Failed to enter the lock within timeout.
       bei Umbraco.Core.AsyncLock.Lock(Int32 millisecondsTimeout)
       bei Umbraco.Core.MainDom.Acquire()
       bei Umbraco.Core.ApplicationContext.Init()
       bei Umbraco.Core.ApplicationContext..ctor(DatabaseContext dbContext, ServiceContext serviceContext, CacheHelper cache, ProfilingLogger logger)
       bei Umbraco.Core.CoreBootManager.CreateApplicationContext(DatabaseContext dbContext, ServiceContext serviceContext)
       bei Umbraco.Core.CoreBootManager.Initialize()
       bei Umbraco.Web.WebBootManager.Initialize()
       bei Umbraco.Core.UmbracoApplicationBase.StartApplication(Object sender, EventArgs e)
       bei Umbraco.Core.UmbracoApplicationBase.Application_Start(Object sender, EventArgs e)

Every time this error occurs, the application pool crashed or the complete server goes down.

Have anyone an idea why this error occurs?

Cheers, Sören