Scenario: Trying for workarounds regarding this issue, I managed to crash the Studio ribbon.
Steps to reproduce: Run workflow at link above. When workflow hangs, click back into Studio, back to browser, back to Studio.
Current Behavior: Execute tab on ribbon vanishes.
Expected Behavior: Execute tab stays put 
Studio/Robot/Orchestrator Version: CE 2018.1.1
Last stable behavior: Unknown
Last stable version: Unknown regarding this issue.
OS Version: Win7 SP1, 64-bit.
Others if Relevant: (workflow, logs, .net version, service pack, etc):
Latest .NET updates installed through 4.6 series.
Problem workflow: Main.xaml (12.9 KB)
Animated gif:
Regards,
burque505
Anil_G
ashokkarale
jinal.shah
Gautham_Pattabiraman
postwick
chandreshsinh.jadeja
vrdabberu
Ajay_Mishra
sven.wullum1
Vyshnavi_Nalumachu